The Mishna says: EVEN THOUGH HE IS WITH HER ON THE SAME BED SHE IS NOT THEREBY DIVORCED.Rava says: If it is on his bed she is not divorced, but on her bed - she is divorced. And a Baraita says: Rabbi Eliezer says: If it is on his bed she is not divorced, but on her bed - she is divorced.
The Gemara asks: Indeed? Is it not the case of a vessel of the purchaser in the domain of the vendor? and if so then we could infer that in the case of a vessel of the purchaser in the domain of the vendor - the purchased acquires possession [which is under debate in Baba Bathra, hence we cannot assume that the law is so clearly established here]?
The Gemara answers: No, we cannot prove the general rule from here; we may interpret the Mishna as applying to a case where the bed is ten tefachim high [in which case all agree that the purchaser acquires possesssion,because it is a separate domain?]
The Gemara asks: But there is the place of the legs?
The Gemara answers: People are not particular of the place [of the legs of the bed]
I do not understand the question regarding the place of the legs:
If the Gemara is referring to a case where the GET fell on the surface of
the bed, which is ten tefachim high - what is the relevance of the legs of
the bed? They are, after all, under the surface of the bed?
If the Gemara is referring to a case where the GET fell under the bed, and
nevertheless considers this area to belong to the domain of the owner of the
bed - again: why ask about the legs of the bed? Why not claim that even if the bed is a separate domain - the ground under the bed still belongs to the owner of the house! And if it is clear that this area is also considered to have been rented to the bed-owner - surely the place where the legs of the bed rest on the floor is also considered to be rented to the bed-owner?
Perhaps a hint can be found later in the Gemara, just before the Mishna, in
the explanaiton of Rashi of the Baraita supporting Rabbi Yohanan, where
Rashi explains: A person who has his wife come into his house - on the
understanding that she comes with the tools and instruments which serve
her". In this Rashi is explaining that tyhe place of these utensils "Kanui
La", in other words: she has the right to use this necessary area, AND THAT
IS ENOUGH!
The Rishonim (Rashba, Ritva, Meiri) are bothered by a similar question and they explain as follows. Although above ten can be considered a separate domain, still if the Kli needs to use the domain of the Mocher it would not be Koneh. (The Rashba adds that the Reshus of the Mocher extends till the sky). However, the bed is high, and therefore it does not impede the use of the ground below it, and thus surely the Mocher is not Makpid, and so goes for the insignificant place of the legs.
D. Zupnik