Much attention was attracted a number of years ago by a photo of a Chareidi man sitting on a plane with a plastic bag wrapped around him.

The man was a kohain and was attempting to avoid the prohibition against Kohanim becoming ritually impure due to contact with a dead body.

The body, however, was not on the plane, a situation which is worthy of its own discussion.

In this case, the concern was that the plotted airpath of the plane passed over a Jewish cemetery close to Ben-Gurion Airport, something which reportedly happens from time to time.

The impurity of a Jewish grave rises above the grave, to infinite heights, and a kohain is thus technically forbidden to “fly” over it, unless he is inside something that serves as a חציצה (barrier) between him and the rising טומאה.

Whereas his action seems extreme and somehow instinctively ridiculous, particularly given the fact that most pious and learned people do not seem to practise such stringency, some discussion is indeed in place.

There are a few reasons why this might not be a valid concern, among them:

1. Flight paths are never cast in stone and can and do change at anytime (making it a likely case of דבר שאין מתכוין) that is not פסיק רישיה)
2. In case of doubt regarding טומאה ברשות הרבים (impurity in a public place,) we are lenient. Even though the plane itself is a רשות היחיד, the doubt is based regarding the ground below, which is a רשות הרבים.
3. The plane itself, being its own “tent” or enclosure could possibly serve as a very effective barrier between the kohain and the rising impurity

The first 2 points are far from simple, but we will focus today on the third:

In order for this point to have any standing, one would first need to show that a plane fits the definition of an ohel (“tent” or enclosure) that acts as a barrier against rising impurity- for example, if the plane itself is made of metal and susceptible to impurity, it might not function as a barrier against it.

Without going into this question (but see Rashi 30b אהל זרוק לאו שמיה אהל ,)it is still far from straightforward, and is tied to the sugya at the bottom of 30b, going onto 31a.

We have established that although the food used for the Eruv needs to be edible and permitted to someone, it does not have to be permitted to the person making or using the Eruv.

For example, a Nazir may rely on an Eruv made with wine, even though he is not allowed to drink it, and a non-kohain may rely on an Eruv made with תרומה, even though he is not permitted to eat it himself.

Further than that, Rabbi Yehuda holds that the Eruv of a kohain may even be placed in a cemetery, somewhere that he is not allowed to go to avoid becoming impure.

The Gemara brings a Beraita that explains that this is because he is able to go there inside a container style cart (see text and Rashi for precise names and definition), which serves as a חציצה (barrier) between him and the graves.

It then links this dispute to a dispute regarding an אוהל זרוק ( a moving “tent” or enclosure.)

Unlike the Tana Kama who holds like Rebbe that such an enclosure does not protect one from impurity outside, Rabbi Yehuda holds like Rabbi Yosi bar Yehuda who is of the view that it does.

This debate seems to relate directly to our case of the plane flying above the cemetery.

The plane seems to be comparable to the enclosed wagon, seeing as it moves, and could thus be a typical case of an אהל זרוק.

That would make our case subject to the dispute between Rabbi Yehuda who is lenient, and the Tana Kama who is stringent.

Should we follow the usual rule of following the majority opinion, as well as the rule that the rulings of Rebbe are accepted over those of his colleagues, things would then not look so good.

The Rishonim also have different views regarding the precise scope of this debate.

Rashi defines a אהל זרוק as an אהל המטלטל , a tent that is moved/movable.

It is still unclear whether this is referring to a “tent” (read:container) that CAN move/be moved, or one that IS actually moving.

The simple flow of our sugya seems to imply that Rabbi Yehuda considers the אהל זרוק to be a valid barrier to the טומאה even while it is moving, otherwise the kohain would not be able to ride through the cemetery inside it. This is how the Rashba understands Rashi here as well, as well as the sugya itself.

However, he also quotes Rabbeinu Chananel who opines that the debate is only regarding a movable “tent” that is currently stationary, but that even Rabbi Yehuda admits that while it is actually moving, it is ineffective as a barrier.

The Rashba considers this later view to be problematic and seems to tend towards the simple meaning in our sugya, but the Ritva seems to adopt it as normative.

Given the fact that the plane is actually moving, some Rishonim would thus invalidate it as a barrier even according to the view that a movable “tent” is a valid barrier.

As such, relying on the plane itself as a barrier is unlikely to be sufficient, and one or more of the other reasons for leniency mentioned earlier in this post might need to be applied. This seems even more clear given that the Rosh explicitly rules like Rebbe due to the rule quoted above.

If all these reasons to be lenient and any others are found wanting, the kohain in the plastic bag have been onto something after all.

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.