His possessions, but not himself - Nedarim Daf 5

Reb Akiva Eiger writes that it would seem from the language of the Ran that when one declares, “I am vowed to you,” he is only prohibiting himself from deriving benefit from his fellow’s possessions, but he would be permitted to derive benefit from the fellow himself. Reb Akiva Eiger wonders as to why this should be the case. Shouldn’t everything be included? (Sefer Beis Arazim says that the Ran could be understood to mean that all benefits are forbidden. As a matter of fact, the Ran in Kesuvos states explicitly that all pleasures are forbidden, even if it does not involve the fellow’s possessions.)

Shalmei Nedarim answers that the expression, “to you” connotes “from something that belongs to you.” The possessions of a person belong to him; his body does not. This is why the vower would be permitted to derive benefit from the fellow, provided that he is not benefiting from his possessions.