Shalom U'Verachah,
I hope you and your family, as well as the Kollel, are keeping well during these difficult times.
On 42b the Gemara says, Isveih Abaye... on Rabah that if a barrel of Tevel broke on one's roof, that the person may bring another vessel to save the Tevel, which challenges Abaye on Hatzalah she'Einah Metzuyah. The Gemara answers that the Beraisa is referring to a case of new barrels which is more common to break. Yet, on Daf 43a the Gemara says Isveih Abaye... about a barrel of Tevel that broke and Rav Yosef answers that Tevel Muchan Etzel Shabbos, so why do Rabah and Rav Yosef need to come onto two different reasons, because I did not notice a Machlokes between Rabah and Rav Yosef specifically on these issues?
Heshi Kuhnreich, Canada
Heshi, thank you for your good wishes. Baruch Hash-m, my family and I are all feeling fine, and I believe that everyone in the Kollel is also well.
1) It seems to me that Rabah on 42b could have answered that Tevel is Muchan, but Rabah wanted to tell us an additional Chidush, that it is frequent that new barrels break, and that we may rely on this Sevara in order to call it "Hatzalah Metzuyah."
2) Here is a better answer, bs'd.
a) First, it should be pointed out that this is only a question on Rashi, because it seems that Rashi is the only one who has the text of "Tevel" in the Beraisa at the end of 42b, as Rashi writes, "We have the Girsa of 'a barrel of Tevel.'" Tosfos (DH Hatzalah) writes that we do not have "Tevel" in our text, and if we look at Rabeinu Chananel we see that he also does not have the Girsa of "Tevel." The Ramban and Rashba also disagree with Rashi's text. Obviously, without Rashi's text of "Tevel" on 42b, it would not be possible for Rabah to answer "Tevel Muchan," so the question is only difficult according to Rashi.
b) I saw that the Maharam (on Tosfos 43a, DH v'Shani Lei) gives an answer to your question. He writes that the reasoning of "Tevel Muchan Etzel Shabbos" has only a limited power. It helps to take away only the problem of "Mevatel Kli me'Heichano" but it does not help to override the rule of "Ein Kli Nital Ela l'Davar ha'Nital," which is the problem on 42b.
c) This rule is in fact stated by Tosfos to Beitzah 36a (DH bed'Tivla). Tevel is of course Muktzeh on Shabbos, and Tosfos writes that therefore it is considered "Davar she'Eino Nital" since one cannot actually do anything with it on Shabbos as long as he has not actually separated Terumos and Ma'asros from it. The Rashba there in Beitzah writes this more clearly: One may not move a Kli for the purpose of Tevel according to Rebbi Yitzchak, because one also may not move Tevel itself. Rav Moshe Feinstein zt'l in Dibros Moshe here (chapter 31, branch 2, page 39, DH v'Hineh) writes that the Maharam did not see Tosfos and the Rashba in Beitzah.
d) We can explain the difference between the Din of Rebbi Yitzchak and the Din of Mevatel Kli me'Heichano as follows. Rebbi Yitzchak maintains that moving a Kli for the purpose of Muktzeh is tantamount to moving Muktzeh itself. Tevel is Muktzeh on Shabbos, as long as it has not been prepared for eating by having Ma'aser separated from it, so it follows that one may not move a Kli for it. The Din of Mevatel Kli me'Heichano is a different Din. Rashi writes in the Mishnah (42b) that according to this opinion, if one puts a Kli into a position where one will not be able to move it, this is like sticking it with glue into that place. It is similar to Melachah because it is reminiscent of building. But this is a different prohibition, not a prohibition of Muktzeh. Therefore, since the prohibition of Mevatel Kli me'Heichano is a lighter prohibition, not a prohibition of Muktzeh, it follows that the fact that there is a way of making the Tevel not Muktzeh anymore, namely by separating Ma'aser, is sufficient to override the prohibition of Mevatel Kli me'Heichano.
Kol Tuv,
Dovid Bloom
Thanks for all the beautiful insights.
Regarding point d:
Nice explanation.
While reading however I thought that we might explain it a bit more simple.(i.e. Not because this is a 'lighter prohibition)
Regarding 'Davar ha'Nital' since the Tevel is now Muktze one is prohibited from moving it - even if it can actually become Mutar in shabos, but since now it is Muktze, one can also not move another Keli for the Tevel (according to Reb Yitzhak of course)
However,if the issue is only Mevatel Keli mi'Heichano? that means there is no problem moving the object, the problem is only when you put it somewhere where it will stay for the whole shabos, but here by Tevel 'you (theoretically) don't know for sure that it will stay there as it can become mutar during shabos. So you didn't 'stick it to one place'...
Anyway, thanks for spreading more torah.
Kol tuv,
M. Porgesz
Yes, Moishy you have explained it very well!
Yasher Ko'ach,
Dovid Bloom