Nedarim, Chapter Four, Mishnah One
This mishnah and the subsequent mishnayoth discuss what is prohibited to a person who is under a vow not to benefit from his fellow. Note that these types of vows can be initiated by either party: Reuven may swear that Shimon may not benefit from Reuvens property and Shimon may swear that he may not benefit from Reuvens property.
1) The only difference between one who is under a vow not to benefit at all from his neighbor, and one who is under a vow prohibiting food benefit, is in respect of walking [on his property] and [the use of] utensils not employed in the preparation of food.
2) If a man is under a vow not to derive food benefit from his neighbor, he may not lend him a sifter, sieve, mill-stone or oven, but he may lend him a cloak, ring, garment, and earrings, and whatever is not employed in the preparation of food.
a) In a place where things such as these are rented out, it is forbidden.
Section one: There are two things which are permitted to one who is under a vow not to derive food benefit from his neighbor that are not permitted to one who may not benefit from his neighbor at all: walking on his property and the use of things not involved in the making of food. The next section of the mishnah will qualify this statement.
Section two: A man who cannot derive food benefit from his neighbor may not borrow vessels which are involved in the making of food, but he may borrow things not involved in the making of food. However, if in such a place, the custom is to rent these things (a cloak etc.) then borrowing them is prohibited. For if the one who cannot receive benefit from his friend borrows these things without paying, he saves the money he would have otherwise had to spend. With that money he may now go and buy food. Indirectly, therefore, he has derived food benefit. Therefore, in such a place borrowing any item would be prohibited.