2,784. Prohibiting Benefit From Everyone
Hilchos Nedarim 7:9
If someone prohibited himself from benefiting from the residents of a city, he may not ask the rabbi of that city to permit his vow. If he did do so, and the rabbi permits the vow, it is effectively permitted, as we discussed in chapter 4.
Hilchos Nedarim 7:10
If a person prohibited himself from benefiting from everyone else, he may still benefit from leket, shich'cha and peah (the portions of the harvest designated for the needy), as well as from the tithe for the needy when it is distributed from storehouses (because any needy person can take it), but not when the farmer distributes it from his home (because then he can select the recipients).