I was at the sea shore again today pondering Rav Shach. The issue is this. Shavuot page 22 side a. The gemara gives one explanation of a Braita. This braita is brought as a question on Rav papa who said a vow does not need a size. The Braita itself says this שני קונמות מצטרפים שתי שבועות אינן מצטרפות. Two vows are joined. Two oaths are not. [That means to say that if one forbids to himself a half size (of a kezait) of a fig and a half size of an apple these two sizes are joined even if he forbid each by a separate vow, The Gemara asks how are two nedarim joined? Go here and there is not enough. Go there and there is not enough. [To transgress the prohibition, one needs to transgress the whole amount of a kezait). Answer: he forbade both by one vow. After this the gemara brings a statement of Ravina to answer the question on Rav Papa.The answer is Rav Papa is talking about lashes, the braita is talking about meila. At this point the gemara is holding that the sages hold there is meila with nedarim. But before this point the gemara thought the sages hold there is no meila with nedarim. [Meila means transgressing. This is the word used to for the case where one uses an animal dedicated to be a sacrifice. For this prohibition there is a guilt offering. The point here is that there is an alternate opinion of R. Meir that there is no meila with nedarim. So what does this mean? It means that if one says this piece of bread is forbidden to me like a sacrifice and then he goes ahead and eats it anyway, he has to bring a guilt offering. This fact is not well known because you do not see this subject much in tractate Nedarim. It actually comes up in tractate Shavuot
So now we come to Rav Moshe ben Maimon [Rambam] and the Raavad. Rav Moshe writes if one forbids to himself a half size of a fig and half size of another fruit even with two separate vows, they are joined to make a whole size. The Raavad asks this is in contradiction to the above mentioned gemara that says only when one makes one vow to forbid two half sizes are they then joined Not with two vows.
Rav Shach says that Rav Moshe ben Maimon [Rambam] holds that after the statement of Ravina, the gemara no longer needs that first answer. For before the statement of Ravina, the gemara thought there is only lashes for nedarim not meila. So the Braita was only talking about getting lashes. And in getting lashes only the fact of transgressing the words of the vows matter. So two separate vows would not be joined. But after Ravina there is no need for this answer. To transgress the isur or meila two separate sizes would be joined just like two separate pieces of any forbidden food.
My question at this point is this only applies to a neder where one says "This food is forbidden to me like a sacrifice." That is the only case where meila applies according to the Rambam. And after all it is the Rambam here that Rav Shach is giving an answer for. But if one says simple "This food is forbidden to me" that does not have meila. So then why does the Rambam write two half sizes that are forbidden by two vows are joined? That should only be the case if each vow ended with "like a sacrifice."
So I do not have energy this minute to show that Rav Moshe holds that only when one says like a sacrifice does the prohibition of meila apply. But in the meantime I ask you to belieeve me that this is in fact the opinion of the Rav Moshe [Rambam]
