This morning I was learning the mishnah on daf 47b and 48a which says that if two people forbid each other to derive benefit one from the other, neither of them can have benefit from items that are specific to their town, such as the town shul. The Mefaresh explains that since both of them have a chelek in the shul, therefore, if one of them uses it, it is as if he benefited from the other's property. The Ran adds that it belongs to them since members of another city do not own a portion of the shul in the city in which these two people live.
However, this evening I was learning Chulin with my chavrusa, and the gemorah on daf 136a says that we learn from the pasuk "V'Asisa Maakeh L'gagecha (and you should make a fence for yourself)" that one is not obligated to build a maakeh for a shul. Rashi explains that since no one has a chelek in a shul and it even belongs to people from overseas, therefore, there is no obligation upon anyone to build a fence for a shul.
This Rashi seems to contradict both the mefaresh in Nedarim who holds that the members of a community have a chelek in the shul and the Ran in Nedarim who holds that people of another city do not have a chelek in the shul?!
Yossie Levitin, Monsey, New York
(1) The key lies in the Gemara Megilah 26a. The Mishnah there 25b states that if one sells a Shul one may buy an Aron ha'Kodesh with the proceeds. The Gemara 26a says that it is only in villages that one may sell a Shul, while a Shul in "Krachin" - large cities - cannot be sold because since people come there from outside and use them, they are considered Shuls that belong to the public. Rashi DH Aval writes that the Shuls in the Krachin belong to everyone and the inhabitants of the city are not the sole owners.
(2) So Rashi in Chulin 136a DH Batei - who writes that the Shuls do not belong to anyone because people who come from overseas also have a Chelek in them and therefore are exempt from Ma'akeh - must be referring to the Shuls of the Krachin. In contrast the Ran in Nedarim 48a DH v'Asurin must be talking about a village Shul because since no one else has a Chelek in the Shul the 7 leading officers can sell the Shul in the presence of the people in town. The idea of the "7 best people in town" is mentioned in Megilah end 26a. However this sale only works for the Shuls in the villages (see Shulchan Arukh OC 153:7).
(3) Similarly the Mefaresh Nedarim 48a DH b'Davar, who writes that the Shul belongs to both of them, must also be referring to a Shul in a village.
(4) The Nafka Mina from the above is that if the 2 people took a Neder not to have benefit from each other and they happen to live in a big city, then they would be allowed to use the Shul because since such a Shul belongs to the whole world this also means it does not belong to anyone in particular - even in partnership - so the 2 people would not be considered as having Hana'ah from each other when they use the Shul.
(5) You might ask on me that our Mishnah does not say it is discussing the Shul of a village, but rather of an "Ir" - a town? However I can answer with the Mishneh Berurah 153:25 that any place where there are not a lot of people coming from outside, is called a village. Even though there are a lot of people passing through periodically, nevertheless since these people are not fixed in the city, but just pass through temporarily, this is still considered a village. So therefore even though our Mishnah does not say "Kfar", but it does not say "Krach" either, so we can say that our Mishnah refers to a town where there are not many visitors who come for a fixed period of time and use the local Shul.
[See also Rashi Yoma 12a DH Krachim who writes that a Shul in a large city does not become Tamei if it receives Nega'im, because it does not belong to anyone specific. Rashi there is discussing a similar scenario as Rashi in Chulin).
Behatzlocho Rabah (wonderful to hear from you, Yossi!)