Eruvin 69-71  The Lomdus of “Bittul Reshus”

Eruvin 69-71  The Lomdus of “Bittul Reshus”

The main theme of this daf relates to the concept of  בטול רשות  and how and when it applies.
We have mentioned before that the mechanism of choice for multiple inhabitants of one courtyard is to make an עירוב חצרות  whereby food is set aside on behalf of everyone in one of the houses, symbolically “joining” them all into residents of the same domain.
This is of course a symbolic mechanism which does not in any way affect the actual ownership of the houses and shared courtyards, and serves merely as a reminder not to carry from a private domain to a public domain proper- something Chazal were concerned enough about to prohibit carrying from one private domain to another owned by different people in the absence of such an eruv.
This eruv can only be done before Shabbos, as doing it on Shabbos resembles מקח וממכר  (commercial activity.)
If one or more of the inhabitants did not participate in the eruv before shabbos, the eruv is essentially ineffective.
This is because although all those who participate in the eruv are considered as if they share each other’s houses as well as their share in the common courtyard, the courtyard is also owned by those who did not participate, and therefore subject to different ownership than the houses of the participants.
This means that no one can transfer items between their houses and the common courtyard or vice versa.
One solution available is the mechanism of בטול רשות , also referred to in the Mishna as נתינת רשות .
The relationship between these two phrases requires analysis in its own right-for one approach, see Rambam Pirush haMishnayos Eruvin 6/1, 6/3 and 6/4 who seems to understand that נתינת רשות sometimes refers to making the eruv and sometimes refers to בטול רשות.
Whereas the phrase בטול רשות  seems to indicate a one-way mechanism by which the owner removes himself from ownership, control, or some other connection to his share in the courtyard (or possibly also his house,) the phrase נתינת רשות seems to indicate a two-way mechanism similar to a gift where the owner “gives over” one of the above at least symbolically to the other inhabitants.
There is a debate between Beis Shamai and Beis Hillel as to whether this may be done on shabbos, and the Gemara explains that Beis Shamai view בטול  as a form of two-way transaction whereby the non-participants  give over their “authority” over the courtyard to the participants, effectively leaving the courtyard owned in its entirety by the participants and making the eruv effective.
Seeing as such transactions are forbidden on shabbos, it may not be performed on shabbos.
In contrast, Beis Hillel view this as simply  סלוק (removing oneself from authority), a one-way mechanism that achieves the goal of making the courtyard owned solely by the participants due to his share being irrelevant, rather than owned by them.
Such an arrangement is permitted on shabbos, and at first glance, it might appear to be a form of הפקר- declaring one’s property to be ownerless- once his share of the courtyard is ownerless, the others remain its sole owners and their eruv is valid/
However, there are limitations that apply to the rules of הפקר  that do not seem to apply here.
For example:
i.                    Hefker needs to be declared in front of three people )Nedarim 45a), yet one person can be מבטל רשות to 2 people, and there is no indication here that someone else needs to be present (Tosfos deals with this issue in Pesachim 4b)
ii.                  According to the view that one needs to be מבטל רשות to each one of the people who were included in the eruv, simply making one’s share הפקר is clearly not enough
iii.                Hefker removes all legal connection between oneself and the object, to the point that anyone else can perform a קנין  (transactional act) on it and acquire it. In addition, the person who declared it הפקר  would need to perform an official קנין  in order to reaquire it- doing so in one’s mind would not do the trick. In this case, there does not appear to be any ability on the part of those who benefit from this בטול to take legal ownership of the property, but the benefit is limited to symbolic permission to carry within the area “as if” they owned it. Furthermore, it does not seem that a legally valid קנין needs to be made by the original owner in order to cancel this בטול.
iv.                It is not at all clear that declaring something הפקר  on shabbos is permitted, as the Ramban points out (Pesachim 4a)- it could be included in the general prohibition of commerce.
The concept of בטול  can be found in various other areas of halacha, for example:
1.      בטול חמץ  – one is required to declare any chametz left in one’s possession before midday on erev pesach “nullified like the dust of the earth.”
According to Rashi (Pesachim 4b,) this seems to be a way of fulfilling the mitzva of תשביתו  (removing chametz from one’s possession) and Tosfos seem to understand that it is a form of הפקר that creates a situation where that mitzva is simply not relevant anymore
2.      בטול ע”ז – an item of idolatry may become permitted if it is nullified by the idol-worshipper- this can done by breaking part of it, possibly a sign of its lack of importance to the owner (see A.Z. 52b.)
Though all 3 usages of this phrase seem to share in common the idea that one is declaring or showing that the item is no longer of importance to him, there is no need to assume that the “lomdus” (logical mechanism) in all three is similar. It is very possible that בטול חמץ  is a real form of הפקר  which בטול עבודה זרה  is certainly not, and that בטול רשות  is something completely different.
After all the phrase בטול  is also used regarding  בטול תורה  (wasting time when Torah could have been studied,) בטול עשה and   (avoiding performing a positive mitzva,)  בטול and none of them have anything to do with הפקר or ownership.
More specifically, whereas בטול חמץ  and בטול עבודה זרה  seem to work on a biblical level to avoid the prohibitions of owning chametz on pesach or an item of idolatry, בטול רשות  is a rabbinical measure which might simply be meant to have a similar symbolic effect  to that of the eruv.
However, there are views in the Rishonim, principally that of the Ramban (Pesachim 4b,) who  seem (at least a first glance) to assume that all three work on a similar mechanism and thus attempt to leave הפקר  out of the discussion altogether.
Although a thorough analysis of the various views as to how these different instances of בטול  work is still required, it is clear that whatever explanation is offered will need to pass the test of the different rules Chazal prescribed for each of them, in the absence of some other “external” explanation for the rule in question. The topic is vast- I have barely scratched the surface of the many sugyas and mefarshim that relate to the topic.
These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 66 בטול ושכירת רשות  on Shabbos and more special eruv leniencies

At the bottom of Eruvin 65b,  a case is brought where 3 sages of the transition/early Amoraic period, Rabbi Chanina bar Yosef, Rabbi Chiya bar Aba, and Rabbi Assi spent shabbos at an inn owned by a non-Jew.
The owner was not present before shabbos for them to hire his “reshus” from him, and according to the view of Rabbi Yehuda that if the non-Jewish resident/owner is not present over shabbos, he forms no barrier to the eruv, they could have made an eruv before shabbos without him, but even if they did, now that he was back, it was no longer valid, and  they asked each other whether  this שכירת רשות  could be performed on shabbos. (there is some debate amongst the Rishonim as to whether they did indeed make an eruv before shabbos and whether they held like Rabbi Yehuda or not.)
The basis of their uncertainty was whether שכירת רשות  is forbidden on shabbos just like making the actual eruv is, or whether it is permitted like בטול רשות  is according to Beis Hillel (see Mishna on Eruvin 69b and Gemara on it)
It seems to me  that the basis of their uncertainty could be as follows.
On the one hand, it could be a form of transaction which effectively gives them control of the space, and is thus included in the prohibition of מקח וממכר  (commerce) on shabbos, just like the actual ערוב חצירות  process is, and like Beis Shamai also view בטול רשות  ( as explained by the Gemara on Eruvin 71a)
On the other hand, it could be simply a form of סלוקי רשות, (removing one’s own rights to the object) like how Beis Hillel view בטול רשות (see also Eruvin 71a) and thus permitted.
A deeper analysis of the conceptual mechanisms by which the above processes work is needed, particularly regarding how שכירות  can possibly resemble מחילה  and just be considered as סלוקי רשות  when the renter clearly seems to be an active part of the process- it certainly seems from this that we are not dealing with a real rental, but some form of symbolic rental with its own set of laws (see Meiri who makes this point.)
For our purposes, we shall note that Rabbi Chanina bar Yosef was in favor of going ahead with the שכירות, Rabbi Assi was against it, and Rabbi Chiya bar Aba suggested that they follow the lenient view of the “elder” Rabbi Chanina bar Yosef and go ahead.
After the event, they asked Rabbi Yochanan about this, and he praised their actions.
This attracted the surprise of Nehardai, given that Rabbi Yochanan had ruled previously that שוכר כמערב דמי  (the one who performs this שכירות רשות  is subject to the laws of one who makes the eruv,) and going by that, he should have been against their lenient treatment of שכירות רשות  as בטול רשות  that permitted it on shabbos.
The Gemara responds that in keeping with the general rule that most principles of eruvin are said to produce leniencies and not stringencies (see Rashi), Rabbi Yochanan’s application of the law of the מערב  (eruv maker) to the שוכר  (renter) only extends to the leniencies of the מערב  and not its stringencies, such as being valid with less than the value of a פרוטה  and the other leniencies listed on the daf.
This could be because Chazal treated  שכירות רשות  as a form of hybrid mechanism which takes on the leniencies of both עירוב  and בטול רשות  and neither of their unique stringencies- alternatively Rabbi Yochanan could have simply been unsure as to which mechanism it follows and ruled leniently either way.
This seems  to be yet another example of how lenient Chazal were with the requirements of Eruvin, even above their normal leniencies applied to all rabbinic laws. We saw this earlier  regarding the rule of הלכה כדברי המקיל בערוב  in that even a minority lenient opinion might be followed in an unsettled dispute (see posts on Eruvin 46 and 47.)

Usually we are not entitled to be lenient in rabbinic matters in two different ways that create  a paradox or situation of תרתי דסתרי .
For example, one may be lenient and daven Mincha after plag hamincha in accordance with Rabbi Yehuda or choose to be lenient and daven Maariv straight after plag hamincha before nightfall in accordance with the Chachamim (see Brachos 27a,) but one may not follow both leniencies and daven both Mincha and Maariv during the time between plag and nightfall.
One must choose whether to treat that time as night or day but cannot treat it as both on the same day, and certainly does not treat it as a hybrid.
Yet, in our case, we are not forced to choose whether to treat the שכירת רשות  process leniently like מערב  regarding using less than a  שוה פרוטה  or treating the שכירת רשות  process leniently like בטול רשות  and permitting it on shabbos- rather  we are able to treat it leniently like both, despite is seeming logically paradoxical.
This is no small thing, and further analysis is required to assess if the above comparison is indeed accurate, as well as the scope of this leniency (for example, does it also apply to other instances of שכירות  on shabbos), but that’s some food for thought for now.
These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 62, 65 Bittul and Sechiras reshus and hotels on Shabbos

After some fascinating diversions into the realm of the prohibition of making halachik rulings in front of one’s Rabbi, respecting the privacy of married couples, ruach hakodesh, and much else, we return to the discussion of the main theme of the chapter’s opening Mishna.

We already know that although from a biblical perspective, there is no prohibition against transferring items on shabbos from one private domain to another adjacent one, even if it is owned by a different person, Chazal prohibited transferring things from one private domain to another if the second domain is owned by a different person.

This prohibition was designed to prevent one from getting confused and transferring from a private domain to a public domain and extends even to transferring objects from a private domain owned by an individual to one which he shares with other individuals.

This was the standard situation with the shared courtyards that multiple homes would commonly  open up to in Talmudic times (still common in older neighborhoods of Yerushalayim and other cities),also applies to the communal spaces and corridors of apartment buildings and gated communities, and to a certain extent, as well to the public space in cities which are enclosed enough to meet the criteria for being considered private domains.

Chazal limited this prohibition to shared spaces where an ערוב חצירות  has not been made- the eruv here does not refer to the physical or symbolic partitions that are necessary to make it into a private domain, but to the eruv process we have discussed before where food is used to symbolically convert the entire area into one single private domain.

There is another option available , known as בטול רשות, where everyone except for one resident can “nullify” their ownership thus making the one resident the halachik owner for the duration of shabbos, also making it one large  private domain.

Though this could be  a reversible decision, it is rather complex and the precise lomdus by which it works requires its own discussion- more of that later.

For reasons discussed in the Gemara (Eruvin 62a,) the option to make an eruv only applies when all residents are Jewish as the symbolic eruv mechanism is not available to a non-Jew, nor is the option of בטול רשות.

The Mishna on 61b discusses the laws when one lives in a courtyard with an idolater (the applicability of these laws to monotheistic non-Jews and a ger toshav are a discussion in their own right, which I hope to address sensitively and correctly at one point.)

Rabbi Meir is of the view that even if there is only one Jew living in the courtyard, he may not carry in or into it, whereas Rabbi Eliezer ben Yaakov holds that so long as there is only one Jewish household  there, no eruv is needed even.

Once there are more than one Jewish households living in the courtyard, Rabbi Eliezer ben Yaakov agrees that an eruv is needed theoretically- however, seeing as the idol-worshipper cannot be part of the eruv, the only way forward is a third mechanism, namely that of שכירות רשות.

Unlike בטול רשות  which does not transfer ownership in any way to anyone else, this involves the עכום renting his rights in the property to the Jewish residents, making them the only halachik owners of the space, after which they can make an eruv amongst themselves.

The Gemara on Eruvin 62a refers to a debate as to the nature and status of this “rental” and notes that it was understandably not common for the non-Jew to agree to such an arrangement.


How does this affect one who stays in a hotel on Shabbos?

Theoretically speaking, a hotel is generally owned by the same person, group of people, or company, and all areas from the rooms to the corridors and public areas should thus be viewed as one large private domain, so long as the entire area is surrounded by halachically acceptable partitions.

As such, one would think that there should be no issues carrying from room to the public areas and versa, within the public areas, or from room to room.

However, this could be a little more complex given that rooms are “rented” out to different people, and there are typically both Jewish and non-Jewish guests, hotel-owners, managers, and other staff staying there at the same time.

If we view this as a regular שכירות , and if שכירות קונה  (renting a property makes the renter the halachik owner during the period of the lease, at least in certain regards,) then the hotel can no longer be regarded as one private domain owned by the hotel owner, but is more similar to a courtyard with multiple houses, each owned by different people.

This would essentially make all the complexities of עירוב, בטול רשות, and שכירת רשות  applicable to a hotel situation.

In truth, the general rule seems to be that  שכירות לא קניא  (a rental does not confer temporary ownership- see A.Z. 16a  but c.f. B.M. 56b and Pesachim 6a, and a topic for another post.)

Yet Strong evidence that these rules indeed apply to a hotel situation can be found on Eruvin 65a, where Reish Lakish and the students of Rabbi Chanina spend Shabbos at a פונדק , where a non-Jew also was renting a room, but was not currently there. The owner, on the other hand, was there.  (A פונדק   generally appears to refer to an inn where people stay temporarily while travelling, both long and short-term  [see Tosefta B.M 8/28 (Leiberman) ]and seems at face-value at least to be equivalent to a modern-day hotel-)

The Gemara relates how they wanted to do שכירת רשות  from the owner but were uncertain whether he had the authority to do this, seeing that the relevant room was rented out to someone else.  It explains that their uncertainty related to a place where the law entitled the owner to evict the renter at any time, but that if he did not have the right to do this, it was clear that he was also not able to perform שכירת רשות.

As a hotel manager or owner certainly does not have the legal authority to evict  guests any-time he wants to(at least in most modern locales,) it seems that one would have to perform שכירות רשות  with any non-Jewish guests themselves.

However, most of the  Rishonim (see Rashba, Ritva, Rosh for example) note that if the owner has a תפיסת יד  (degree of control) over the rented property still, such as the right to store property there, he can certainly perform the שכירות רשות  even if he lacks the right to evict the tenant.

They prove this from the fact that even שכירו ולקיטו  (the hired laborer) of the owner may perform this שכירות given their connection to the property, and an owner with rights to keep property in the rooms is certainly not less than a שכיר.

As such, seeing as hotel owners or managers (who ostensibly have the law of a שכיר) store hotel furniture, decor, electronic devices and other property in the rooms, have the right to enter to inspect or clean the rooms (at least when guests are not present) and maintain general responsibility for the rooms, it seems that they certainly would have the ability to perform this שכירות רשות, assuming it is even needed. (One could  counter  though that seeing as all the items kept in the rooms are for the use and  benefit of the guest during his stay, this is not the same level of תפיסת יד  that one who may use the rooms for his own storage-after all, the manager or even the owner usually cannot just store his own private things in the rooms at his whim!)

There is also another case at the bottom of the daf where a similar question regarding שכירת רשות  in a פונדק  arose, adding more strength to the argument that hotel settings might also be subject to these requirements, though still subject to the points raised above.

It seems that for whatever reason, as far as the requirements of eruv and שכירת רשות  are concerned, we do consider שכירות  as a form of קנין.

Perhaps these laws are simply not dependant on absolute ownership but more on utility and control- this would make sense given the reason that Chazal required eruv chatzeiros  to prevent people transferring from one domain to another- as such, it is not objective ownership that is important but rather the appearance of residence. (there might be reason to differentiate between short-term and long-term rentals (more than 30 days as well, but that is beyond the scope of this post.)

In order to avoid all the complexity regarding these issues, many people perform  שכירת רשות  in hotels where possible (and so I have seen Moreinu haRav Asher Weiss שליט”א, though  he told me it might not really be necessary.)

Based on the above arguments, doing so with the owner, manager, or other appropriate staff member of the hotel seems to be acceptable normative practise.

 However, there is also strong reasoning in favor of those who do not do so for short stays less than 30 days- of course, please see below disclaimer as usual!

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha

Eruvin 60 and 61 Do Gedolim have “Ruach haKodesh”

In a rather unusual responsa, Rav Chaim of Sanz (the Divrei Chaim,) founder of the Sanz dynasty of Chasidim (Y.D. 1/105,) dealt with the issue of a school teacher who had told his students that Rabbi Chaim Attar, author of the famed “Ohr haChaim” super-commentary on the Chumash, did not write his work with “ruach haKodesh” (“holy spirit-“ loosely translated as “divine inspiration” and possibly described as a form or means of prophecy.)

The teacher was fired from his position, and the Divrei Chaim was asked whether this was the correct decision, to which he responded in the affirmative, going so far as to say that the author of any great Torah work who is fit for it, can be said to have ruach-hakodesh.

This position seems rather problematic at first glance, given that the Gemara (Sanhedrin 11a and various other places) brings a Beraisa which states that ” משמתו נביאים האחרונים חגי זכריה ומלאכי – נסתלקה רוח הקודש מישראל, ואף על פי כן היו משתמשין בבת קול (Once the last prophets, Chagai, Zecharia, and Malachi died, “ruach haKodesh” departed from Israel, and nevertheless,they would make use of a “bas kol.”

It continues to tell how a voice from heaven once proclaimed that there was someone worthy of having the שכינה rest on him like Moshe Rabbeinu, but the generation was not worthy, and the sages assumed it was referring to Hillel!

This Beraisa seems to imply a number of things, among them:

  1. Ruach hakodesh is tied to prophecy, and when prophecy ceased, so did it.
  2. Even arguably the greatest sage of the early Tannaic period, Hillel himself, did not have “ruach hakodesh.”

The Divrei Chaim’s claim is also particularly ironic, given that the Ohr haChaim himself (Bereishis 6/3 ( states emphatically that there is not even a ריח (smell) of “Kodesh” left in our time, never mind “ruach hakodesh.” (thanks to )

Yet at the bottom of Eruvin 60b, Rav Idi quotes an important rule regarding Eruvin in the name of Rabbi Yehoshua ben Levi.

Although there is a rule that an entire city (at least a walled one) is considered like 4 amos, and thus counts very little towards the 2000 amos a person is allowed to walk on shabbos, this rule is not absolute, and only applies in certain circumstances.

For example, if a person’s shabbos base is outside the city, and the city fits in its entirety into the 2000 amos of his techum, it only counts as 4 amos and he earns the rest of the length of the city in the same direction on the opposite side of the city. (כלתה מדתו בסוף העיר)

However, if the 2000 amos of his techum ends somewhere in the middle of the city (כלתה מדתו בתוך העיר) , then the city counts as part of the 2000 amos, and he may not move past the point where it ends, even within the city itself.

After reporting this view in the name of Rabbi Yehoshua ben Levi, Rav Idi comments that “אין אלו אלא דברי נביאות” (lit- these are only matters of prophecy), as on a logical level, there should be no difference in the law between the two cases.- either the city should count as part of the 2000 amos either way, or be considered as 4 amos in both cases!

Rava then takes issue with Rav Idi’s comment by bringing evidence from the next Mishna that this distinction indeed exists, after which Rav Idi holds his ground and explains the Mishna in a way that it does not serve as precedent for our case, in a discussion that carries over onto Eruvin 61a.

There are various ways to interpret the comment of Rav Idi regarding Rabbi Yehoshua ben Levi’s ruling being “דברי נביאות”

  1. This could be understood literally as coming to praise and agree with Rabbi Yehoshua’s ben Levi’s words by saying that they were derived prophetically by him , without any earlier source or logical principle to back them up. This is the approach that Tosfos takes, bringing another sugya (Bava Basra 12a) to back up his view. In Tosfos haRosh, the Rosh seems to take a similar approach.
  2. Rashi, possibly unwilling to entertain the notion that Rabbi Yehoshua ben Levi experienced prophecy or even “ruach hakodesh,” takes a more nuanced view of this approach. He too, understands that Rav Idi views the ruling of Rabbi Yehoshua ben Levi positively and as being, at least to some extent, prophetic, but does not attribute this prophecy to Rabbi Yehoshua ben Levi himself. Instead, he explains that in the absence of any logical or textual evidence for his rule, he must have received it as a tradition from his Rebbe going back to something heard מפי הגבורה (by Moshe from Hashem) at Sinai! This explanation is also brought by the Ritva.
  3. Rabbeinu Chananel, seemingly unwilling to treat this ruling as any form of prophecy, seems to understand that Rav Idi simply meant that it was a גזירה of Rabbi Yehoshua ben Levi himself, without textual support or obvious logical basis. He also seems to understand that Rav Idi meant to weaken Rabbi Yehoshua ben Levi’s statement, not strengthen it.
  4. As mentioned above, it is also possible that Rav Idi is not coming to strengthen the status of Rabbi Yehoshua ben Levi’s ruling, but rather to weaken it, and possibly even rule against it. His labelling of his words as דברי נביאות could be somewhat sarcastic, as if to say that the only way he could have come up with something like that was through prophecy, which he clearly did not have.
  5. Without going so far as in the above point, it could be that Rav Idi is attributing a certain degree of prophecy to Rabbi Yehoshua ben Levi, but views such a source for halacha as inferior to one grounded in textual and/or logical support, and perhaps unauthoritative, given the principle of לא בשמים היא.

The Rif and the Rosh both state that we rule like Rabbi Yehoshua ben Levi because Rava brings a Mishna to support them, even though Rav Idi was able to explain the Mishna differently. Though they point out that Rav Idi’s main intention was not to rule differently, it seems that they acknowledge that he indeed did hold differently, or at least made his comment to weaken the authority of Rabbi Yehoshua ben Levi’s ruling rather than strengthen it. A similar approach can also be seen in the Meiri.

It seems clear from the above that most Rishonim do not take the comment of Rav Idi to mean that Rabbi Yehoshua ben Levi actually had prophecy and/or “ruach hakodesh, even if this is the most simple reading of the text.

It seems compelling that the reason they did not do so might well be because this would contradict the often quoted earlier source that “ruach hakodesh” and “prophecy” are either equivalent or at least go together, and that both ended with חגי זכריה and מלאכי .

The Tosfos, on the other hand, who do understand Rav Idi’s comment literally, need to deal with this issue, and this takes us into a study of the sugya he quotes in Bava Basra, as well as a fascinating Ramban, which I hope to go into in a couple of days when we revisit this discussion, Hashem willing.

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 57 and 58 Nature trails on Yom-Tov and measuring the techum with Google Earth

Whereas most of daf 57 focusses on the extended boundaries of cities, in particular another possible leniency that according to some allows an additional 70+ amos to be added to the city- proper’s boundaries, the Mishna at the bottom of 57b takes us into new territory- the correct method for measuring the techum.

In a time where walking between close-by city’s was normal and often required, much effort was made by each community to measure and mark the techum of their city, and 2 people worked together to do this rather complex task.

This requirement, however, is FAR from obsolete and should be done in any community where leaving the halachik boundaries of the city on Shabbos or Yom-Tov is common- this would include walking between two suburbs of a city that are separated by more than 141 amos of open space, a fairly small area which is enough to make them considered two different cities halachically, as well as towns bordering natural areas where people like to enjoy the trails (Ramat Beis Shemesh being a great example, with our lovely nature walks.)

The method set out by Chazal, and hinted at in pessukim, was that a rope measuring 50 amos would be held at either end by each partner at chest level- after shifting forward 50maway from the city, this would be repeated until 40 such measurements had been taken, and the techum boundary would be marked at this point .

This process would be done 8 times, at each end of the 4 sides of the square/rectangle that the city had been fit into, after which the final process of squaring the techum itself could be carried out.

The Mishna tells us that ” אין מודדין אלא בחבל של נ’ אמה לא פחות ולא יותר” – We may only measure with a rope of 50 amos, no more and no less.

The Gemara bases this length on the passuk describing the width of the Mishkan’s courtyard. “ורוחב חמישים בחמישים” – its width was 50 with 50. The seemingly spurious “with 50” teaches us that it should be measured with a rope of 50 amos, and this seems to serve as a precedent that things which require precise measurements should be measured with a rope of 50 amos.

The Gemara understands ( as per Rashi’s explanation) that any more than this would be too hard to pull tight enough, resulting in some sagging and a shorter measurement for the techum.

Similarly, any less would result in too much stretching and hence a larger techum than required.

The Gemara proceeds to discuss what material the rope must be made of and seems to conclude that it needs to be made from flax, due to its relative accuracy.

Whereas the length of the rope used appears to be non-negotiable, it is still not clear whether the Mishna is telling us that a rope MUST be used, or simply that if a rope is chosen, it must fit the required length.

It is also not clear whether the Gemara requires the rope to be made of flax and nothing else or whether it is simply allowing anything as accurate as flax, and by “kal vachomer”, anything more accurate .

One Nafka Minah ( practical ramification) of the first question could be if one wanted to measure the techum with the car’s odometer, or with google Earth tools.

If the Gemara requires rope and only rope, then despite its greater accuracy and efficiency, this would not be acceptable.

If on the other hand a flax rope was simply the lower limit of how accurate the measure may be, then these modern tools would clearly be fine and perhaps even better.

In a Beraisa brought by the Gemara, Rabbi Yehoshua ben Chananya points out that there is nothing better for measuring than “chains of steel”, but the Navi ( Zechariah 2/5 , in a vision describing the future messianic period) describes how Yerushalayim will be measured with a “חבל מדה”( a measuring rope.)

Although at first glance this might seem to prove that the rope is an absolute requirement even when more efficient methods are available, it is also possible to interpret this in a way that is consistent with the second more lenient possibility.

It could be that Rabbi Yehoshua is not bringing the passuk to exclude more efficient or easier methods of measuring, but just to exclude steel chains or other bulky materials which though more technically accurate, are not usually used as measuring tools due to their heaviness .

After all, handling a 50- amah wide metal chain is hardly a simple task even for two strong men!

The phrase “חבל מדה” would then not be taken completely literal but would teach us that the method used for measuring must not only be reasonably accurate but also something efficient enough to qualify as a “measuring rope.”

It is also possible that Rabbi Yehoshua ben Chananya is not bringing the passuk as a stringency which comes to exclude more accurate or more efficient methods, but as a leniency to teach us that even though a rope is not the most accurate of methods, it is still acceptable!

In looking through the Rishonim, I did not see much discussion about this question, but was delighted to see that the Meiri actually interprets Rabbi Yehoshua precisely like the second suggestion above, and rules that steel chains ( and by implication other more efficient and accurate means ) certainly may be used .

He notes that some disagree and are stringent, and I found in my search that the Or Zarua (2/163-Eruvin) indeed does so.

Amongst the later Poskim, I have not found anywhere that the Shulchan Aruch or Rema discuss this issue, but did find that the Aruch haShulchan( O.C.399) takes it for granted that Rabbi Yehoshua came to exclude steel chains and that a rope specifically must be used.

As I first heard from Rav Asher Weiss שליט”א , the Rema ( C.M. 25/2) rules that even though we usually follow the rulings of the later authorities assuming that they have already seen and taken into account the rulings of the earlier authorities, if they were clearly not aware of an earlier authority’s ruling, a contemporary poseik can follow that earlier authority.

It is well known that the Meiri’s work was not known to the Mechaber, and while it might have been known to the Aruch haShulchan ( it certainly was to the Mishna Berura who quotes him) it is not clear how much of it was known to him.

Given that הלכה כדברי המקיל בערוב , there thus certainly seems to be strong reasoning in favor of following the lenient approach and using the modern tools of technology to measure the techum, provided it is done with the agreement of a top-level Talmid Chacham.

It should of course also be borne in mind that a car’s measuring device, as well as the standard distance tool on Google-Earth measures total distance including the vertical component of slopes.

In contrast, the laws of Techumim generally allow one to consider only the horizontal component of the total displacement between the two points.

As such, unless one uses technological tools that can measure the “as the crow flies’ horizontal component of the displacement, one could land up being much more stringent than required.

This brings up one more major leniency that could be applied to the “Table Mountain ” conundrum. (for those who have not seen the earlier posts, this is a unique feature of the City of Cape-Town, which surrounds the over 1000m base to summit peak on 3 sides. We have been discussing whether the entire mountain or parts of its can be included in the city-limits, given the rules of עבור העיר and the 4000 amos cut-off point.)

The vertical height of the mountain is well over 1000m above the sea-level neighborhoods- Up and down, that’s about 2000m from the “walking ” distance measured by google earth that can be deducted from the techum limits once one leaves the last house of the city (or from the 4000 amos cut off point for עיר העשויה כקשת!)-unfortunately, the almost 6000 metre gap measured through google earth between the two opposite legs of the city still seems to result in far too much empty space to include the whole mountain in עבור העיר.

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 55 The extended techum and Table Mountain continued, and self-sacrifice for Torah

Today’s daf has a solid mix of aggadic material and a return to the technical rules regarding how to work out the extended shabbos domain of a city.

I wish to start with the halachik side of the daf, כדרכינו בקודש, even though some of  the aggadic material precedes it, and hope to return to the Agadot thereafter.

For the sake of clarity, the אגדה includes all content in the Talmud that does not involve the halachik (legal) process, including מדרשי אגדה  that comment on the narrative portions of the Tanach or complement them and ethical and other advice- see מבוא התלמוד attributed by many to Rabbeinu Shmuel haNagid, one of the first of the Rishonim  and published at the back of מסכת ברכות  for his exact definition, though note that his view on the source and authority of agada is subject to much debate amongst the Geonim, Rishonim and later authorities (my in-depth Hebrew article on this subject is currently work in progress.)

We have already learnt that the general rule is that the techum (shabbos domain) of a city in which one is permitted to walk on Shabbos  stretches to a maximum of 2000 amos (between about 800-1000 m) from the last house in the city’s halachik borders (recall that 2 houses separated by 141 amos or more of empty space might be considered halachically to be in 2 different “cities.”

We have also seen recently that this applies in theory, but that in practise, the distance one may walk from the last house of the city might be significantly more, for 2 reasons:

  1. The limits of the city proper might stretch significantly beyond the last house, such as when the shape of the city is irregular (non-rectangular or grid-like) in which case some open space might be included in these limits themselves.
  • The techum of the city, while theoretically stretching 2000 amos from the end of the city-proper, is effectively measured by placing a rectangular block at the corners of the city and not a circle, meaning that while the shortest this techum will extend is 2000 amos, at the diagonals, it will extend significantly more (by pythagorus.)

The first rule is not applied universally, and one needs to be familiar with all the different shapes discussed in the sugya and which other shapes would be treated like these shapes, before jumping into using this potentially very useful tool.

For example, while a circular city has a square circumscribed around it, including the empty-space outside the circle but inside the square in the city proper itself, and a trapezium seems to be  viewed as if it is was the smallest rectangle that it could fit inside, a rectangular city is left as is, and  a parallelogram could be more complex.

There is also some discussion as to whether the square needs to be on the North-East-South-West axis of the world or can face any direction.

One of the more fascinating shapes describes is the עיר העשויה כקשת – a city in the form of a bow (or rainbow.)

The Beraisa  initially taught us that we draw a fictitious line from the one extreme of the bow to the other (this line is known as the יתר and represents the string which would be pulled back by the arrow before the arrow is released ) and view all the empty space between this line and the houses of the city as part of the city-proper, measuring the techum from this line.

However, Rav Huna rules that this only applies if the length of this line is no more than 4000 amos, allowing someone whose shabbos base or house is in the middle of this line (the spot where the arrow would be placed)  to walk to the city within his own 2000 amos (see Rabbeinu Chananel for his full explanation.)

However, if the length of this line is more than 4000 amos, the empty space is not included in the city limits, and the techum is measured from each individual house.

According to Rabbah bar Rav Huna, the space between the bow and the middle of the line also needs to be less than 2000 amos in order to include the empty space in the city proper, but according to his son, Rava, this is not necessary, and Abaya supports  his lenient view, seeing as anyone in the city could reach the middle of the  line by walking first to the end of the city.

Tosfos suggests that  according to Rava son of Rabbah bar Rav Huna, if the distance between the bow and the line itself is less than 2000 amos, the 4000 amos  restriction on the length of the line might not apply due to the same reasoning of Abaya- the midpoint of the line could be accessed through the 2000 amos or less route to the bow itself- this too is subject to debate amongst the Rishonim.

Tosfos further assumes that the 4000 amos limitation on  a bow-shaped city does not apply to the case discussed earlier where a house or row of houses  protrudes outside the grid of the city. In such a case, even if it is more than 4000 amos to the fictitious parallel row of houses we draw on the opposite end, the empty space is included in the city proper. 

Although he attempts to explain the reasons for this distinction, he admits that the Ri (one of the two most senior Baalei haTosfos) holds that this limitation applies to that case as well. Once again, this topic has generated much discussion and debate amongst the Rishonim and can also affect L shaped cities.

Though there is so much more to learn and understand regarding the above and other related issues (those whose appetite has been whet might enjoy the extensive treatment of this issue in the Rashba, Ritva, Meiri and other Rishonim) ,it is now clear that including the empty natural space between the extremes of an irregularly shaped city is far more complex than it might have originally seemed.

We are not even close to theoretically allowing climbing table mountain on shabbos or Yom-Tov  even without the other multiple halachik challenges one would face (though as per accompanying images from google Earth, it seems that the “Lions Head” Mountain might fall completely within the techum of Cape Town City, and at least on Yom-Tov where carrying is less of an issue, with the guidance of the local Rabbis and eruv experts, the gorgeous trail up and down MIGHT indeed be permissible.

In the beginning of the daf, various explanations are given of the passuk “לא בשמיים היא ולא מעבר לים היא  ” – (it is not in heaven nor is it on the other side of the sea.)

I would like to focus for a minute on the explanation of רב אבדמי בר חמא בר דוסא  who derives by implication that although the Torah is indeed reachable for us, even if it were not, we would be liable to reach to the sky and cross the sea in order to get it.

There are times indeed when Torah goals seem unobtainable to us, and although we should be encouraged by the fact that in essence, they are vey much obtainable, we need to push ourselves and be prepared for self-sacrifice in order to achieve these goals despite how unobtainable they seem.

The Rosh Yeshiva זצ”ל , Rabbi Tanzer, was a prime example of someone for whom no goal was too far away when it came to his life’s mission of spreading Torah.

Starting with the literally huge distance diagonally over the Atlantic that he set out on together with his young wife, leaving behind their friends and extended families in an era of very limited communication for what was at first envisioned as a 2 year stint in Africa, he moved onto the virtually impossible goal of turning what was then a virtual spiritual wasteland into a vibrant Torah center.

This was not a job he fulfilled from the ivory tower of an office, or even a classroom, but one that took him literally from door to door begging parents to enroll their children in his fledgling Torah day-school.

Almost 6 decades later, the Yeshiva College campus has served  as the largest center of the Johannesburg Jewish Community and educated generations of students who span the Jewish world, from Rabbis and Torah teachers to businessmen and professionals, as well as some combinations of both.

Returning briefly to the more technical parts of daf, the rather superficial summary we have done above and the fastest reading of the daf reveals how an understanding of mathematics is essential to being able to make the complex calculations needed for taking full advantage of the shabbos techum- One also clearly needs some conception of how much a factor raw mathematics was in Chazal’s reasoning, something that only a good knowledge of both Chazal’s methodology and mathematics would allow.

Though those who knew him know that Rabbi Tanzer was first and fore-most a Rosh-Yeshiva who was most at home in the Beis-Midrash and who got the most joy out of those students who went on to become serious Torah Scholars, he always pushed his students to excel in their general education as well, creating a generation of students with the knowledge required not only for their chosen careers, but also for understanding many areas of Torah that are beyond the reach of those who lack this knowledge.

The Gaon of Vilna, broadly considered the greatest Torah figure in many centuries, was famous for stating that it is impossible to fully understand the Torah without understand all the forms of general (I prefer not to use the term secular) wisdom (see “haGaon” by D.E. Eliach for citation) , something he himself accomplished, and though neither he nor our Rosh Yeshiva would encourage one to give more priority to general studies than to Torah, chalila, I personally have found great benefit from the general education I received under Moreinu haRav Tanzer and his team, not just in my business, but most importantly in so many areas of my Torah Study.

Although reaching the wisdom of the Vilna Gaon is certainly like reaching for the sky, and building en empire of Torah like the Rosh Yeshiva did is certainly also above most of us, we can learn from him to be prepared to try our absolute best, and if we do so, the results will speak for themselves, with Hashem’s help!

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 52 and 53  The enlarged techum, nature walks on Shabbos, and Agada

Queenstown/New-Zealand: techum options?

In loving memory of our dear Rosh-Yeshiva of Yeshiva-college, South Africa, Moreinu haRav Avraham Tanzer of blessed memory, who passed-away peacefully Tuesday night in Johannesburg.

It has been my great privilege to work in the international travel space, with the opportunity to show people so many of the wonders of Hashem’s creation around the world.

One of the highlights of spending a Shabbos in such places is the opportunity to enjoy spectacular shabbos walks amongst gorgeous scenery.

Of course, while going for a pleasurable walk on shabbos is a great way of fulfilling the mitzva of oneg shabbos, and might thus even be considered a mitzva as far as certain laws are considered (making an eruv techumim for example,) one has to be aware of the halachik issues involved, amongst them the prohibition against carrying on shabbos outside a closed area and the prohibition of leaving one’s shabbos domain/techum.

One who camps out in nature is very limited by the later and will usually only be allowed to walk within a 2000 amos range of his tent, even if he is not carrying anything.

In fenced resorts, so long as the entire area is מוקף לדירה  (fenced for the sake of human habitation,) one might be able to measure the techum from the fence of the resort.

Moreover, in resort towns and cities, one might be able to measure the techum from the last house of the city, baring in mind that legal city limits and halachik city limits are not the same thing, and that a gap of more than  140 amos between houses or property walls might be considered a break between two halachically separate cities.

This can mean that in spread-out suburbs or resort towns, one might not even be able to walk from one side of the town to the other, and would be limited to 2000 amos from the building or fenced-in property one is staying in, placing a rather substantial limitation on one’s walking options on Shabbos.

The Mishna at the bottom of Eruvin 52 has some consolation, however, which can be very significant:

Although the space between houses that is permitted for them to be considered part of the same town is rather small, the idea of the עבור העיר – extended halachik limits of the city (as in a שנה מעוברת  [leap or extended year] or אשה מעוברת  [pregnant woman], or according to a different version debated on Eruvin 53, אבר (limb) or extra components of the city) means that substantial amounts of empty space might indeed be included in the halachik city limits.

For example, if a house of the city protrudes on its one side (the north-east corner as per Rashi’s example)  forming an irregular shape, we draw a fictitious protrusion opposite it (on the south-east corner) , and then “square” the city with a perpendicular line from the original protrusion to the fictitious one, including the empty space in-between within the city proper.

We will also  see  (Eruvin 57b) that this also applies to other irregularly shaped towns that do not form a typical square or rectangle style grid, and by using this method, large areas of open natural space can often be included in the limits of the city proper, before we even start measuring the 2000 amos techum around it, which we have already seen is also squared in a way that makes it effectively significantly bigger (Eruvin 49b.)

Chazal determined (Eruvin 57b)  that the techum of shabbos needs to be measured physically with a rope 50 amos long, a point which Rashi uses on our daf (Eruvin 52b at the bottom) to explain the view that there is a 15 amah safety net for someone who mistakenly left the techum, a topic I would love to analyze further in the context of halachik safety-nets in general.

As such,  whether one may rely on satellite images such as those available on google earth to measure this techum, or even on a car’s distance metre, is for a different discussion, one I hope to go into when we get there, Hashem willing.

The process of measuring the techum was taken very seriously in Chazal’s time, and markers were placed on the roads to show where the techum ends, as Rashi on our daf also points out.

Given that sufficiently measuring the techum for a once-off trip might not be feasible, and does not even seem to be common -practise in fixed  Jewish communities, possibly because of the common use of Eruvin, the practical use of these very powerful tools might be limited by pragmatism, but one who knows these laws sufficiently should be able to at least pre-measure the route of any planned  nature-walks as well as map-out the shape and geography of the town before shabbos, in order to ensure than everyone can enjoy these gorgeous walks in a halachically correct manner.

In my first post on this masechta, I recalled how despite my fondness for it, there was some concern raised as to how I would be able to keep up with contemporary relevant posts given its technical nature.

I noted then that besides for the great opportunity to focus on some of the most important rules of Eruvin, Shabbos, and halachik psak in general, there are also plenty other topics in the masechta, and even a fair amount of aggadic material, even if less so than  in the first two masechtos in the shas.

In fact, my affection for Eruvin started during my time as a Rebbe in Yeshiva-College, under the late Rosh-Yeshiva Rabbi Tanzer זצ”ל  and יבל”א  his son Rav Dov Tanzer שליט”א, himself a revered Torah giant of note who mentored me not only in chinuch but in the intricacies of constructing eruvin in the many resorts we used for school Shabbatonim and seminars I ran.

I also pointed out that sometimes Chazal used some of the most technical of discussions to teach us some of the most relevant general principles of halacha and Torah life, and that as we focus on the equally essential minute details of each subject, we need to constantly keep our eyes open for these messages.

Today’s daf is one of those, and while it starts with the extremely technical methods used to calculate the extended borders of a city, it moves onto a wealth of aggadic (non-halachik) material.

There is much discussion from Chazal to the Rishonim and beyond as to the status and role of this kind of aggadic material, which the Rambam teaches us contains the secrets of the Torah (Pirush haMishnayos/intro to חלק), but without detracting chalila from their sanctity and importance, Rashi  (Shabbos 30b ) explains that Agadot are a genre used to draw close the hearts of people and get them interested in the material about to be taught.

Chazal were fully aware that as human beings, we love stories and allegories, and that before, after, and sometimes in the midst of our delving deep into complex halachik intricacies, some of their great non-halachik teachings and traditions should be brought delivered in this format.

Going further, the Amora Rabbah was always particular to start every learning session with a   מילתא דבידוחתא, literally a matter of a joke )Shabbos 30b.)

Given that even the everyday chatter of Torah scholars requires study )A.Z. 19b) , there is little doubt that even these jokes contained wisdom, and are certainly different to the extremely frowned upon ליצנתא  (cynical or mocking humor) which Chazal (Derech Eretz 5/5) warned us against.

Our beloved Rosh-Yeshiva, Rabbi Tanzer of blessed memory, as with everyone in his life and career, followed in Chazal’s path, and always started his words of Torah with a joke or story, which in his wisdom he linked and made relevant to the material he was about to teach.

A master of human-nature almost impossible to find, we can never replace him, but we can certainly do our best to follow in his ways, if only our everyday chatter could come close to the level of his.

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 50 Tannaic versus Amoraic authority and “רב תנא הוא ופליג”

In the Mishna on 49b, we are told that  a person who is on a journey home on erev Shabbos and realizes that it is starting to get dark and he is still not within 2000 amos of his home or city (but is within 4000 amos) , may designate a place that he knows along the way as his shabbos base, thus allowing himself to walk a further 2000 amos from that designated space and reach his home on Shabbos.

The Mishna stresses though that simply declaring his shabbos base to be under a particular tree does not do the trick- he needs to specify where under the tree, such as at its base, otherwise “he has not done anything.”

Rav and Shmuel dispute what the Mishna means by “has not done anything.”

Rav is of the view that he has disqualified his current position from being his shabbos base by showing that he does not intend it to serve this purpose, but has also not successfully declared a new shabbos base, and he is thus confined to his 4 amos for the duration of shabbos (as explained by Rashi, but see Rambam Eruvin 7/5 who appears to rule like Rav but understand that his current position remains his shabbos base.)

Shmuel, in contrast, holds that so long as the entire area under the tree is within 2000 amos of where he is, he may walk to the area under the tree and 2000 amos from it.  However, seeing as he did not specify which area under the tree is to be his shabbos base, this area has the law of a חמר גמל  (donkey and camel man- see earlier post on Eruvin 35) and he may only walk within 2000 amos of the furthest part of it from where he wishes to go.

Most of our daf is dedicated to discussing this issue, and on 50b, the Gemara brings a Beraisa in support of Shmuel and in refutation of Rav, yet the Gemara answers that bringing a Beraisa against Rav is not sufficient to prove him wrong, seeing as “רב תנא הוא ופליג” -Rav is  a “Tana” and argues (with other Tannaim.)

It is taken as axiomatic throughout the shas that the Tannaim (sages of the Mishnaic period) are more authoritative than the Amoraim (sages of the Talmudic period) and that an Amora may never disagree with a Tana unless he has another Tana to back him up- The main job of the sages of the Gemara is to interpret, reconcile, and adjudicate between the Tannaim but not to disagree with them.

Yet on our daf, in addition to various other places in the shas, we are told that the leading Babylonian Amora of the first generation of Amoraim, Rav, is an exception, and is considered a Tana who may and does argue with Tanaim.

In another place where this exception is made (Kesubos 8,) Rav and Rabbi Yochanan are both quoted separately as stating that a groom can be counted in a minyan but a mourner can not (what precisely this is referring to is discussed there.)

The Gemara brings a Beraisa to refute Rav which says that both grooms and mourners may be included in the minyan but responds that רב תנא הוא ופליג- Rav is a Tana and argues with the Beraisa.

It brings the same Beraisa to refute Rabbi Yochanan and answers that the Beraisa is talking about ברכת המזון  (grace after meals) in which the mourner may be included towards the required 10 for זמון בשם  and Rabbi Yochanan is talking about the שורה  (the line for comforting the mourners) in which the mourners may not be counted.

There appears to be some logic in this distinction, given that the purpose of the minyan for ברכת המזון  is to allow Hashem’s name to be mentioned in the zimun, and a mourner is equally obligated in being part of this than anyone else.  However, the purpose of the minyan for the שורה  is to comfort the mourners, and the mourners are not part of the mitzva of comforting themselves.

Yet despite this seemingly obvious distinction, Tosfos points out that the Gemara saw this as a “forced” distinction and preferred to use Rav’s status as a Tana to answer the difficulty on him.

In contrast, seeing as Rabbi Yochanan does not have the status of a Tana (the Rabbi Yochanan quoted in a Beraisa [Nazir ] is a different person, a Tana by that name, possibly Rabbi Yochanan ben Nuri,) the Gemara had no choice but to resort to this distinction.

Given the apparent superiority of Rav over Rabbi  Yochanan to the point that Rav had the status of a Tana and was thus able to argue with Tanaim, and Rabbi Yochanan did not, it seems rather inconsistent that the rule of thumb throughout the Talmud is that we follow Rabbi Yochanan in cases where he argues with Rav.

To solve this apparent inconsistency, it is necessary to examine various possibilities as to why a Tana is more authoritative than an Amora.

1.       One  possibility is that the Tanaim were closer chronologically to the giving of the Torah, and thus their מסורת  is considered purer and more uncorrupted.

2.       Another option is that the Tanaim were objectively greater in learning than the Amoraim.

3.       A third possibility is that the Amoraim simply had  different roles to that of the Tannaim because  once Rebbe sealed the Mishna, its words become like the authoritative ruling of the great court which could no longer be over-ruled. As such, their only role and sphere of authority was now in interpreting, reconciling, and adjudicating disputes in the Mishna.

Whereas possibilities 1 and 3 above are less likely to allow for individual exceptions, the second reason might leave the door open for an unusually great Amora whose learning was equal or greater to that of some Tannaim  to be able to argue with at least some of them.

According to this reason, it could simply be that Rav’s greatness in learning was such that it was recognized throughout the Talmudic world as being on par with the Tanaim, something that other Amoraim lacked.

However, we would then need to explain why Rabbi Yochanan is considered more authoritative than Rav, despite Rav being on par learning-wise with Tannaim and his apparent failure to be considered as such.

According to the first option, it is certainly possible that the generation that formed the transition between the Tannaim and Amoraim (see Meiri/introduction to Avos who clearly defines this transition, and  includes Rav in this list but not Rabbi Yochanan) were close enough to the מסורות  of the Tannaim  that their מסורות  was sometimes treated as almost or equally as pure.  We would still need to explain why Rabbi Yochanan, though living in the same period, was not included in this transition generation but still was considered more authoritative than Rav when it came to disputes between the two of them.

According to the third reason, it is very possible that when Rebbe and his  court sealed the Mishna as authoritative over all future generations, they excluded certain specific Amoraim who were particularly close to them in terms of the chain of transmission from this limitation, and even conferred them with the type of neo-Tannaic semicha (ordination) needed in order to be exempt from this ruling.

An example of Rebbe’s close relationship and partial ordination of Rav before he went to Bavel can be found in Sanhedrin 5a-5b  where Rabbi Chiya arranged for רשות  (permission to rule) to be given by Rebbe to Rabbah bar bar Chana and to Rav. It is apparent from that sugya that Rav was actually the greater of the two in learning!

It is important to note that this was not actual סמיכה  as in the ordination passed down from Moshe, which might or might not have been held by Rav and/or Rabbi Yochanan, but נטילת רשות להורות  (permission to rule) and to be exempt from liability for errors made- this on its own does not serve as proof of Rav’s exclusion from submission to the Tannaim, but simply as an illustration of his extra closeness to Rebbe.

As Rabbi Yochanan remained in Eretz-Yisroel and might also not have had this same connection to Rebbe, it is possible that he simply never received this special status from Rebbe, and was thus bound by Rebbe’s decree that the words of the Tanaim would be henceforth binding on the Amoraim.

This distinction between Rav and Rabbi Yochanan seems to be mentioned by the Ritva (quoted in Shita Mekubetzes, Kesubos 8a) in order to answer our original question- He explains that we follow Rabbi Yochanan over Rav in a local dispute between the two of them due to Rabbi Yochanan’s greater wisdom but that unlike Rav, Rabbi Yochanan never had the “luck” to be ordained as a Tana in the way that Rav had been.

From the fact that the sugya in Kesubos chose to use Rav’s superior status to refute the proof against him from the beraisa rather than give the answer it gave to uphold Rabbi Yochanan against the same beraisa, it seems that this status is strong enough that it is preferential at least to a “forced” answer, and we indeed see various places in the Rishonim (see Tosfos/Menachos 5a for example)  where they say that instead of giving whatever answer is given to reconcile Rav’s words with a seemingly contradictory beraisa, the Gemara could indeed have chosen to use his superior status as a Tana to answer the question.

Yet in contrast, from the fact that the Gemara regularly poises difficulties on Rav’s statements from various Tannaic sources, it is clear that finding a “non-forced” way of reconciling such difficulties is preferable to resorting to his Tannaic status, which is evidently significantly weaker than that of regular Tannaim.

we see further that some Rishonim in our sugya rule like Shmuel against Rav (see for example Tosfos Eruvin 49b and Piskei Rid Eruvin 50b), even though the halocho almost always follows Rav in a dispute with Shmuel, specifically because the beraisa supports him, implying that this status is not absolute, and that although he may indeed argue with a Tana, other Tannaim are more authoritative than him and the halocho follows them against him, at least when Shmuel rules against him (see though Rif and Rosh who base their ruling like Shmuel on other factors as well.)

It is also clear that his status as a Tana is limited to his ability to argue with Tannaim, but does not limit other Amoraim’s ability to argue with him, or in the case of Rabbi Yochanan in particular, to be considered more authoritative than him when involved in a direct dispute with him.

As such, it seems that the third possibility we raised fits best with Rav’s exceptional status, and that the superiority of Tannaim over Amoraim is not based on either their chronological precedence or their innate superiority in learning, but rather on the authority given by Rebbe’s Beis Din to them over Amoraim, something he likely excluded transition figures such as  Rav from.

While his court excluded Rav from the requirement to submit completely to Tannaim, he did not include him in the list of Tannaim that Amoraim are required to submit.

As a curveball, there is a fourth approach which I would like to entertain.

Perhaps, there was never a specific court ruling or decision that Amoraim may not argue with Tannaim, but it was simply an unwritten agreement that developed amongst the Amoraim of the transition period, for some of the above-suggested or other reasons, which later became established practise.

Amongst the Amoraim of this transition period, some were more accepting of this approach than others, and while Rabbi Yochanan went along with it, Rav did not, as least as far as he himself was concerned.

We can recall that Rav was generally fiercely independent in his approach to halachik decision making and did not accept the many rules of psak that delegated more authority to certain Tannaim over others (see recent  post on Eruvin 47), rules which Rabbi Yochanan did accept and have generally  been accepted to this day.

As usual, there is much more to bring, much more to analyze, and the Rambam’s view on all of this  requires its own unique treatment-hopefully we shall have the opportunity to revisit this again when the topic next occurs.

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 46 and 47 Rules of psak: הלכה כדברי המקיל בערוב, דעת יחיד בשעת הדחק, ספק דאורייתא לחומרא ,ספק דרבנן לקולא

This daf is heavily concentrated with some of the most important principles of psak halacha that it is even harder than usual to do it justice.

We shall suffice with a brief explanation of some of them and some notes based on an initial analysis of how they are applied on this daf, hoping to build on what we have already done and continue to do based on their application in other sugyas.

The Mishna on Eruvin 45b recorded a dispute between Rabbi Yochanan ben Nuri and the Chachamim whether a person can acquire his shabbos techum during twilight of erev shabbos if he is asleep.

Rabbi Yochanan ben Nuri rules that he can, whereas chachamim hold that seeing as he was not awake at the time, he did not acquire his 2000 amos from the place where he was, and is limited to the 4 amos in which he was.

Rabbi Yehoshua ben Levi is quote by Rav Yaakov bar Idi as ruling in accordance with Rabbi Yochanan ben Nuri’s lenient opinion.

Rabbi Zeira asked Rav Yaakov ben Idi whether he heard this from Rabbi Yehoshua ben Levi as a specific ruling relating to this case, or deduced it based on a general rule of his, which the Gemara identifies as “הלכה כדברי המקיל בערוב” -the law follows the lenient opinion regarding Eruvin.

Rav Yaakov bar Idi replied that he heard it as a specific ruling, and the Gemara explains that this specific ruling was needed in addition to the rule to teach us that this rule applies even when the lenient opinion is a דעת יחיד (single opinion) against the majority opinion, such as in the case of Rabbi Yochanan ben Nuri versus the Chachamim.

It is not clear at this point whether this leniency is meant to apply only to this case, or whether this case now serves as a precedent for all the laws of Eruvin, or perhaps even all rabbinical disputes

If the former is correct, we need to explain why this dispute in different to all other disputes regarding Eruvin. If the middle option is correct, we need to explain why the laws of Eruvin are treated more leniently than other rabbinical laws, where we are only lenient when there are as many lenient views than stringent ones.

If the latter is correct, we need to explain why we are so lenient with all rabbinical disputes to the point of pushing aside the general rule of אחרי רבים להטות – following the majority, and defend this statement against any other statements of Chazal that imply the opposite.

We also need to investigate whether Rabbi Yehoshua’s rule of הלכה כדברי המקיל בערוב is merely an application of the general rule of ספק דרבנן לקולא (as in the third option above), with the assumption that an unresolved dispute has the status of a doubt, and whose lenient applications are thus shared with all unresolved rabbinical disputes, or whether it is an independent rule that has its own unique leniencies not shared with other rabbinical disputes (as in the middle option above.)

We have touched on a similar question in an earlier post (Eruvin 35-36) where we discussed ספק עירוב לקולא – the rule that in matters of doubt regarding the validity of an eruv, we are lenient, and there is appeared that the Gemara understood this as simply an extension of the general rule of ספק דרבנן לקולא.

Assuming that a ספיקא דדינא ( a doubt as to which authority the halacha follows) is an extension of the concept of ספק דרבנן, this would imply that a dispute regarding Eruvin should also simply be an extension of the rule of leniency in the case of a dispute regarding any rabbinical law.

However, from a question asked by Rava on the Gemara’s understanding of Rabbi Yehoshua ben Levi’s statement, it seems that he understands that disputes regarding Eruvin have their own unique leniences.

Rava asks why there was even a הוא אמינא (initial thought) that we would not follow a lenient single opinion against a stringent majority opinion when it comes to Eruvin?!

He points out that this should be obvious, seeing Eruvin is a rabbinical requirement, and in rabbinical disputes, we always follow the lenient opinion, even if it is an individual against the majority!

Various proofs are brought to dispute this assumption of Rava, and this issue is far from resolved at this point, but from his question, it certainly seems that he understood that his colleagues saw Rabbi Yehoshua ben Levi’s lenient view regarding Eruvin to be unique to Eruvin.

Though Rava’s assumption seems to be rejected, the Gemara clearly seems to understand than in another unique area of rabbinical law, namely the laws of mourning, the rule of הלכה כדברי המקיל באבל applies even when the lenient opinion is a single authority versus the majority!

More than that, Tosfos seems to understand that this rule that we follow the lenient opinion in the laws of mourning applies even on the first day of mourning which is דאורייתא (biblical) in nature, suggesting that this might be the case regarding biblical laws of Eruvin too (such as the larger techum of 4 parsah (about 16 km) which some view as deorayso, or when enclosing a real public domain), certainly a huge חדוש (novelty!)

Given that the usually undisputed rule regarding biblical laws is ספק דאורייתא לחומרא – in disputes we follow the stringent opinion, this is nothing short of remarkable, and we cannot escape the need to distinguish between the laws of mourning and possibly also Eruvin, from other rabbinical, and even biblical laws.

There is a fairly well- known dispute amongst the Rishonim regarding the status of the rule of ספק דאורייתא לחומרא .

The Rambam (see Issurei Biah 18/17, for example) opines that this rule is itself only rabbinical in nature, and that on a biblical level, one is not required to be stringent in the case of a doubt- the Torah by default forbids things that we know are forbidden and not things whose forbidden status is subject to doubt.

In contrast, when it comes to the status of rabbinical laws, he is of the view that all rabbinical laws start out with biblical status by default, based on the commandment of לא תסור (do not go against their words…see for example intro to M.T)

Although the various leniencies Chazal applied to their own laws can still be explained based on the fact that the Torah gave them the power to both make and define their own laws, in the case of a doubt, this is not necessary, given that the Rambam considers all doubts to only be subject to rabbinical law, and the Rabbis chose to be stringent with biblical doubts and lenient with their own.

This means that theoretically, in cases of doubt, Chazal have the authority to apply any leniencies they choose, even if the doubt is biblical in nature- they simply chose to be stringent most of the time.

In the case of mourning laws and possibly Eruvin, it is thus quite legal for Chazal to choose to be lenient even in cases of biblical level doubt, and perhaps out of sensitivity to a mourner already in such a sad state, and a person stuck outside his techum on shabbos, they chose to be lenient.

Whether this can be extended to following a single lenient opinion against the majority in a biblical matter is less straight-forward, as it is possible that even the Rambam admits that when there is clear majority on the side of stringency in a biblical dispute, it is a biblical requirement to follow the majority, based on אחרי רבים להטות .

It could be possible, however, that the Rambam holds that אחרי רבים להטות only applies when the dispute has come to the great Sanhedrin, but that a dispute that has not come before the great Sanhedrin had no such law, and remains a bona fide ספק , over which Chazal have total control.

However, some other Rishonim )see for example Rashba, Kiddushin 73a regarding Mamzer) are of the view that the requirement to follow the stringent opinion in case of doubt is a biblical requirement, and according to them, it seems impossible for Chazal to be able to push this rule aside in biblical aspects of Eruvin and the laws of mourning.

The mere fact that Tosfos suggests that the laws follows the lenient opinion even in biblical disputes when it comes to mourning and Eruvin, as well as the proofs he brings for it, seem to offer support for the Rambam’s view!

When it comes to most of the laws of Eruvin and mourning which are clearly rabbinical, Chazal clearly have total authority over their own laws, and if for the reasons suggested above, or other reasons, they chose to treat Eruvin and mourning even more leniently than their other laws and follow even a single lenient opinion against the majority, the were certainly within their mandate.

For further analysis, particularly regarding whether we follow this leniency even against the majority, the Ramban’s long treatment on the daf is essential reading.

We have seen above that although regarding the laws of mourning, and possibly also Eruvin, we may follow a single lenient opinion against a stringent majority, this is not necessarily the case in other rabbinic laws.

Whereas we are usually lenient in cases of doubts and disputes regarding rabbinic laws, where the stringent opinion is the majority, the majority might still prevail.

Yet there is a time where it seems to be permitted to follow a lenient single opinion against a majority stringent opinion, under certain circumstances, and that is the case of שעת הדחק – an emergency.

There is a debate (Niddah 2a) between Rabbi Eliezer and Chachamim regarding whether a woman who has not had a period in 3 months and then has a period may assume that until that moment, she was still pure- this would affect the purity status of whatever she was in contact with before.

According to Rabbi Eliezer, everything she was in contact with until now is treated as pure, whereas the Chachamim rule that anything susceptible to becoming impure from contact with a Niddah that she was in contact with over the 24 hours prior to her period is considered impure.

This is a rabbinical rule due a concern that she was already a niddah earlier, even though on a biblical level, we would be lenient.

Rebbe commented that he once mistakenly thought that the law is like Rabbi Eliezer and declared the items in question to be pure.

When he later discovered that the law was like the Chachamim, he did not rule them to be impure, saying that כדאי הוא רבי אליעזר לסמוך עליו בשעת הדחק – in an emergency, one may rely on Rabbi Eliezer.

The Gemara understands this to mean that unlike Rava’s suggestion, we normally follow the stringent majority against a lenient single opinion even in rabbinical disputes, and only in a שעת הדחק, the minority view may be followed.

It follows from this that even according to Rava’s antagonists, a דעת יחיד may be followed in an urgent situation, at least in a rabbinical matter.

What is not clear yet is the scope of this rule:

  1. Does it apply even to a biblical level dispute? According to Rambam’s above quoted view, it is certainly possible, but according to the stringent views that hold a biblical doubt is subject to biblical level stringency, it seems less likely that שעת הדחק would override that rule.
  2. Does it apply to any dispute, even one already resolved, or only to an unresolved dispute- The Gemara seems to take it for granted that this is limited this to an unresolved dispute (possibly similar to that between Rabbi Yehuda and Chachamim regarding the times for Mincha and Maariv- Brachos,) and that in a dispute that has already been resolved, שעת הדחק would not be a factor. It is still unclear, however, what the Gemara means by a resolved dispute- is this only one that has been resolved by Sanhedrin, do even the Amoraim count, or even post Talmud Geonim and Rishonim?
  3. What is the definition of שעת הדחק as far as this leniency is concerned- Tosfos seems to identify two different levels of שעת הדחק !

The above questions can have immense ramifications in many areas of contemporary halacha, and as we move through the daf cycle, we hope to collect more evidence to help us answer them!

Later on Eruvin 46 and moving onto 47, we move to a different set of rules of psak halacha.

Here we deal with the weight given to various Tannaim against one another when a dispute is given.

Various rules of thumb are given, amongst them:

  1. The halacha follows Rabbi Akiva against a single colleague of his
  2. The halacha follows Rabbi Yossi even against a majority
  3. The halacha follows Rebbe against a single colleague of his

Various other now well-known such rules are also stated, after which רב משרשיה claims that none of these rules actually apply, meaning that each case is in fact to be treated on its own merits- bases this on various ruling of Rav which seem to negate these rules.

After various examples brought to back this claim up, it becomes clear that even those who accept these rules must accept that there are some exceptions. היכא דאיתמר איתמר – in a place where a definitive ruling was made against the general rule, that ruling overrides the general rule. Only in a place where no definitive ruling has been made, do we apply these rules of thumb.

Incredibly, Rav does not except the existence of these rules at all, and even in undecided cases, leaves it up to the individual current authority to rule according to which argument makes most sense to him.

As Rabbi Yochanan does except these rules, the irony is that by the rule of thumb that we follow Rabbi Yochanan against Rav, it should follow that these rules are indeed authoritative, and Rashi on the daf says so explicitly, but what is to force those who choose to follow Rav to accept a ruling based on a rule they do not accept in the first place? Seems Kind of like what came first, the chicken or the egg, but in truth has a lot to do with the power of מעשה בית-דין which still applied to an extent in the time of Rabbi Yochanan!

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.

Eruvin 41 and 43 Landing on shabbos, Flying Elijah, and תחומין למעלה מעשר

One of the nightmares faced by the Torah observant traveler is the possibility of a flight being delayed and arriving at the destination airport on Shabbos.

While whether being on a plane per say on shabbos poises any halachik problems is a subject deserving its own discussion, once a person is already in the air, this is no longer within his control.

However, on landing, one is phased with various issues.

Some of them could be faced at the airport itself, if the entire airport is not one large private domain, or if entry forms needs to be filled in on arrival, not to mention luggage handling.

However, one of the most challenging issues is if and how one may get home or to the nearest Jewish community  from the airport.

Even if one is able to leave one’s luggage at the airport and walk, one must deal with the issue of תחומין, the main topic of our perek.

The opening Mishna of the perek taught us that if  a person left his techum (shabbos domain) on shabbos, even by force, he is not permitted to return on shabbos and is confined to the 4 amos radius he currently finds himself in, a seemingly very harsh ruling for a rabbinical prohibition.

This applies even if he is inside the techum of a house or city.

It follows that if a person left the techum that he found himself in during twilight on erev shabbos, whether the departure city or wherever he was in the air at the time, something that doesn’t take very long on  a plane, he might be required to stay within 4 amos of wherever he lands up on shabbos, and not even be able to walk within the techum he has landed in.

The rule that an enclosed area is considered like 4 amos (also discussed in our current dapim)  might allow him to walk within in the airport itself, depending on how that sugya is interpreted and concluded, but leaving the airport would be forbidden.

In truth, this is not a totally new question from the age of aviation but is tied to an old question regarding people who disembark from a ship on shabbos.

In our Gemara, Rav Chananya asks whether the laws of techumim apply more than 10 tefachim above the ground or not.

At first glance, it seems that this must have something to do with the fact that  an area more than 10 tefachim above the public domain is either a private domain (if it has the minimum width) or a מקום פטור , and walking on it is thus considered insignificant when it comes to techumim.

The Gemara immediately clarifies that a pillar that is more than 10 tefachim high and 4 tefachim wide, part of it within one’s techum and part of it outside the techum, may certainly not be used as a legal way of leaving the techum. This is because it is considered ארעא סמיכתא (solid or supporting ground,) a phrase we have seen before regarding land that slopes at a comfortable gradient for walking up  as well as the area below 3 tefachim in a public domain.

In this context, Rashi explains that because it is fit for walking on (presumably due to its flat and wide nature), walking on it is considered הלוך מעליא  (proper walking) and the laws of techumim certainly apply.

It therefore limits the question to a pillar or raised area that is less than 4 tefachim wide, which is harder to walk on , to someone jumping from inside his techum to outside it, or according to a different version,  to a boat in water more than 10 tefachim deep, which is also considered to be 10 tefachim above the ground.

It seems from this that the question about whether the laws of techumim apply above 10 tefachim or not has nothing to do with it being a private or exempt domain as opposed to a public domain or Karmelit, but rather to do with the fact that it is not an area fit for normal walking.

This requires further analysis, but moving on through the sugya, the Gemara suggests various proofs that the laws of techumim do not apply above 10 tefachim.

The first proof is from a case in our Mishna, involving a boat at sea, which the Gemara now seems to take for granted is considered to be above 10 tefachim from the ground .

The Mishna brought the case of various Tannaim who were on a boat on shabbos. Once they had left the techum, they were technically not allowed to move outside the 4-amah radius they were sitting in at the time shabbos started.

Yet Rabban Gamliel and Rabbi Elazer ben Azaria walked anywhere on the boat, in keeping with their rule that an enclosed area is treated like 4 amos.

Rabbi Akiva and Rabbi Yehoshua, who did not accept this leniency when it came to someone who left his techum on shabbos, predictably stayed within their 4 amos.

If the laws of techumim do not apply above 10 tefachim (like in a boat at sea,) their stringent action makes no sense.

As such, the Gemara wishes to conclude that the laws of techumim  do indeed apply above 10 tefachim.

This proof is rejected given the possibility that laws of techumim do not apply above 10 tefachim but they still wanted to be strict on themselves, in case they passed through shallow water which put them within 10 tefachim of the seabed.

The Gemara brings another two proofs which are both rejected, but now that we have seen that the Gemara takes the view that a boat is to be treated as being higher than 10 tefachim so long as the water it is sailing in is more than ten tefachim deep, I will proceed for now to the final attempted proof.

The Gemara brings a case where someone made an oath that he will be a nazir on the day that the son of David (Mashiach) comes.

Such a person must act like a nazir during all weekdays going forward, seeing as mashiach might have come that day  already and he is simply not yet aware of it.

However,  on shabbos or Yom Tov, he does not have to act like a Nazir.

The Gemara assumes at first that this is because Eliyahu haNavi needs to accompany him and is not permitted to travel so far out of his shabbos domain to do so- apparently even though he is able to fly (an assumption whose halachik significance needs its own discussion of course.)

It thus wishes to conclude from this that the laws of techumim indeed apply above 10 tefachim, otherwise flying such a distance would not represent a problem for him.

The Gemara refutes this proof, given that the passuk in fact tells us that Hashem will send Eliyahu “לפני בא יום ה” – BEFORE the day of Hashem comes, namely the day before.

As we were promised that Eliyahu would not come on a Friday, to avoid disturbing our busy shabbos preparations (itself quite an astonishing statement about the importance of shabbos preparations,) it follows that Mashiach will not come on a Shabbos, and he does not have to act as a nazir.

The Gemara then asks why he is not also exempt from  his vow on a Sunday- after all, seeing as Eliyahu cannot come on Shabbos because of techum issues, Mashiach cannot come on a Sunday- it wants to prove from the fact that he is not exempt on Sunday that Eliyahu could indeed come on shabbos, because there is no prohibition of techumim above 10 tefachim from the ground!

The Gemara answers that it unable to derive from this that there is definitely no issue of techumim on shabbos because it is possible that this was unsure whether techumim apply above ten tefachim or not.

Due to this uncertainty, the vower must take into the account that Eliyahu (who knows the halacha even if we don’t)  might have come on Shabbos, and thus must act as a Nazir on Sunday out of doubt.

However, that does not mean that we can prove from here that there is certainly an issue of techumim above 10 tefachim.

As such, the core question regarding whether the laws of techumim apply above 10 tefachim remains unresolved in the Gemara.

Although we are strict regarding his vow, keeping with the rule of ספק דאורייתא לחומרא , as far as the rules of eruvin themselves are concerned, it follows that we might apply the general rule that in matters of doubt ספר עירוב לקולא .

Assuming that this rule in turn is a derivation of the general rule of ספק דאורייתא לחומרא (something we touched on briefly in an earlier post but that requires further analysis,) it would then follow according to the opinions that תחומין   are biblical after 4 parsa (about 16 km) ,  this leniency might not apply if he has travelled more than that amount since twilight on erev shabbos, an almost certainty with air travel. (see however Ramban, who raised and rejects this distinction.)

Putting the above concern aside, it follows that where prohibitions of techumim are involved, we might be lenient and someone who has travelled through the air, like one who has travelled through the sea, has not transgressed any techum related prohibitions and is thus not subject to the 4 amos restriction.

However, it is still not so simple.

Besides for the question of the larger biblical techum, there is also the question of when and where his shabbos base is determined to be.

After all, if there are no techumim above 10 tefachim, and he was at sea or in the air during the critical twilight period of erev shabbos, he had no techum to become his shabbos base at that time, and it could be argued that he thus has NO shabbos base other than his own 4 amos.

If this were true, then even if disembarking were permitted, and even if he were to be allowed to enter the terminal building,  he would not be allowed to leave the port or the airport on shabbos!

The Ramban notes that he has seen many who have the custom to indeed stay in port under such circumstances.

He suggests that this might be based on the Raavad who understands the Gemara as concluding that we are strict out of doubt regarding techumim above 10 tefachim, not only regarding the vow, but also regarding the laws of Eruvin, an exception to the general rule of ספק עירוב לקולא.

He rejects this view out of hand, and then suggests that it might be due to the above concern regarding him not having any shabbos base at all.

Bringing various sugyos and Rishonim as support, he concludes that this is not a concern, and that in the  absence of a person’s shabbos base being defined during twilight, it is defined as the first valid techum he enters on shabbos itself, in this case the port or city he has arrived in .

Given that, he could technically walk as far as anywhere within the city and within a 2000 amah radius of it.

This would obviously only apply if the port, the parts of the city he walks through, and his home  are halachically considered within the same city (with gaps of less than about 140 amos between the houses or enclosed property’s walls,) something that might apply in city airports but not in many international airports that serve large cities but are situated outside the halachik city  boundaries itself.

Furthermore, unlike a boat which sails in the water till the moment it reaches port, a plane reaches 10 tefachim of the ground just before landing, far away from the airport terminal on a long runway ( a point I saw was raised by Rabbi Daniel Dombroff of New Jersey in a brief online post on the subject.)

Even with the Ramban’s reasoning,  his first valid shabbos base would then be by the landing site, which is unlikely to be in an area that is מוקף לדירה  (surrounded for purposes of dwelling) and is almost certainly in an area larger than a בית סאתיים  (5000 squares amos or about 500 square metres,) and unlikely to be within the techum of the city (though once we square the city and its 2000 amos to define its effective techum, the later is certainly still possible.)

As such, he would only have 2000 amos from that point, and it is likely that by the time he gets to the terminal building, he will have already left his techum and thus at best, be confined to the terminal, and at worst be confined to the 4 amos he is dropped off in.

This seems to be the  basis of common practise to avoid leaving the terminal building, even if the terminal is within the techum of his city.

However, I see some theoretical reasoning for being lenient regarding walking from an airport too, when the terminal is within the city’s techum, in a similar way that the Ramban was lenient in allowing one to walk home from the seaport so long as the port is within the techum of the city.

This is because the plane itself is more than 10 tefachim above the ground, even once it has landed.

Even though some opinions are stringent with a wagon, considering it to be ארעא סמיכתא , a plane while taxiing is very different to a wagon for various reasons, among them:

i.                     It is in a state of continuous and forced motion and cannot simply stop when it wants.

ii.                   It is not only difficult, but both dangerous and forbidden to walk around on it during the taxi stage. (I was interested to see that in a different context, for this and other reasons, מראה הבזק חלק ה brings reasons for leniency even in a wagon or high motorcar)

As such, there is a strong case that his first viable shabbos base to be encountered is not the point at which the plane lands, but at the point where the plane stops, which is far more likely to be within 2000 amos of the terminal or even within the techum of the city.

This is obviously far simpler when an airbridge is used, rather than a bus system, given that there are bona fide partitions around the whole area he will be walking through.

In practise, due to the extreme complexity of this question and the many variables which can change the halacha, it indeed seems hard to be lenient and allow one to leave the terminal building.

It goes without saying that one should do one’s absolute best to ensure a good safety net of time between anticipated landing and shabbos to allow not only for usual arrival procedures and travelling home, but for a reasonably normal delay, and if it is clear that one will land after shabbos once on the plane, to request permission to disembark before take-off.

However given that this is a common issue, perhaps Jewish communities could be encouraged to  get an eruv expert to map the techum of their city and establish whether their airport is indeed within its techum, in which case local halachik authorities  could rule that  in cases where staying at the airport over shabbos is an extreme destruction of one’s Oneg shabbos and/or involves serious discomfort, walking home or to a community center or member’s home might be a valid option.

Though I have not researched the geography of Moscow, it could be that based on the below link,this is precisely what Russia’s Chief Rabbi once did!

These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.