Shabbos 102 The evasive מכה בפטיש (hammer-blow)
One of the most difficult categories of forbidden work on Shabbos must be the melacha of מכה בפטיש, literally “striking with a hammer.”
After all, when a hammer is used constructively, it will usually be used as part of other forbidden categories of work, such a building, and when it used to destroy things with no positive intention, it will usually be מקלקל (a destructive action,) which is only rabbinically prohibited .
Yet this is indeed list in the Mishna (Shabbos 73a) as one of the 39 categories of work forbidden on shabbos, and it is essential to understand what it is.
The Mishna on our daf lists this melacho as one of those which has no minimum quantity required for liability.
Rashi gives both a general rule and an example of this melacha.
He gives the example of the hammer blow given to a stone by those who hew stones, after it has been cut out of the rock but not completely detached .
The stone is then hit with a hammer which causes it to detach and fall from the rock surface.
This is the final stage in the act of hewing a stone, and Rashi then tells us the general rule that the final stage of any melacha makes up the melacha of מכה בפטיש . He told us this rule back on daf 73a as well.
In truth though, numerous difficulties can be raised with both the rule and the example.
Firstly, as Tosfos points out, a forbidden category of melacha needs to involve an action performed in the work of the mishkan, and no quarry work was involved in that at all ( there were no stones in the mishkan, and constructing an altar from hewn stone was actually forbidden- note also how the Aron, Menorah, and Shulchan were all made of one single piece of beaten gold, and NOT of anything that had been cut into parts and then joined together !)
Secondly, if מכה בפטיש is the final stage of any מלאכה, surely it is already included in that מלאכה itself , and why should it get its own category? Does that mean that any melacha done from start to finish would incur two punishments , one for that particularly מלאכה , and one for completing it ? If so, one would expect that to be discussed .
However, this definition of מכה בפטיש does not originate with Rashi, but actually goes back to the Talmud itself (Shabbos 75b) where Rabbah and Rabbi Zeira both tell us that anything that involves completing a מלאכה is מכה בפטיש.
Tosfos appropriately does not disagree with the rule cited by Rashi, but chooses rather an example that did take place in the work of the mishkan , namely the final hammer blow given to strenghen the vessels of the mishkan once they were ready .
Does this melacha perhaps apply to the final act in a creative process even if that process does not involve a forbidden melacha ?
If so , where do we see such an example – after all, if it is a creative act of work that wasn’t in the mishkan, it will usually be included in the toladot of that melacha .
The key might lie in a Yerushalmi often quoted by our teacher, haGaon haRav Osher Weiss שליט”א ( various teshuvos on electricity in מנחת אשר חלק 1 וחלק 3 for example )
The Yerushalmi (Shabbos perek 7/ halocha 2) accounts that Rabbi Yochanan and Reish Lakish spent 3 and a half years studying the matter of 39 melachos.
They found 39 Tolados ( derivatives) of each melacha.
Whatever melacha they were able to fit into one of those, they included in one of those .
Those that they could not include in one of those were included in מכה בפטיש .
It seems clear from this Yerushalmi that there exists NO melacha that is not forbidden on shabbos.
Every possible melacha, however it is defined, either falls under one of the 39 categories, their derivatives , or the מלאכה of מכה בפטיש.
Rav Weiss himself suggests the relatively radical idea that for this reason, any activation of an electric circuit fits under the prohibition of מכה בפטיש .
Although the Bavli gave a different definition, namely גמר מלאכה, and the rule is that one does not follow the Yerushalmi when it contradicts the Bavli, he contends that it is possible that the Bavli did not mean to exclude these “left out” melachot from מכה בפטיש but simply to also include the completion of any melacha .
However, as he himself is fully aware, many poskim before him rejected this possibility, and were most likely fully aware of this Yerushalmi.
Far from me with my barely existent understanding of the subject to argue, but those who do not follow this view regarding electricity have all these Poskim to rely on ( of course, electricity remains forbidden for numerous possible other reasons given, but there could be many נ”מ)
Perhaps what the Yerushalmi really means is that COMPLETING any melacha, even one that doesn’t fit into the forbidden categories, is still forbidden because of מכה בפטיש .
However it follows from this classification that unlike other melachot, some of which one could transgress just by doing some or most thereof ( even if one is sometimes exempt due to “בעשותה” ) , one would have to actually complete the goal of these “left out” melachot in order to transgress.
If one learns this way, there is no disagreement between the bavli and the Yerushalmi at all- מכה בפטיש indeed includes all “left all” melachos , but only the completion of them.
In fact, it is also stated in the same halacha on the Yerushalmi that גמר מלאכה is מכה בפטיש,
Admittedly, this might not be the simplest reading of the Yerushalmi, but it allows for a simpler reading of the Bavli and also avoids the need to say that the Bavli and Yerushalmi have such a basic difference in understanding the melacha, one that the Rishonim do not seem to mention at all ( though see the Rambam , for example in Pirush haMishnayos to perek 7 which Rav Osher suggests as a support for his words .)
Of course , we would now have to test all the examples given in the gemara of this melacha, as well as those on our daf that Rav and Shmuel argue about, before we can really see if this thesis can stand its ground .
We would also need to define exactly what מלאכה is , and what kind of גמר מלאכה is meant by the Gemara- is it the completion of any melacha, just the completion of a כלי, or just the completion of a מלאכה not already included in the 39.
Lots of work to do, but its late …