Who is he working for? TB Nedarim 36

The Mishnah on daf TB Nedarim 35b lists other tasks that one may perform for someone who is prohibited by vow from benefiting from him. One of the tasks concerns a Kohen, priest, in his official capacity. “And he sacrifices for him the bird nests, i.e., pairs of birds, pigeons and turtledoves, of zavin (see Leviticus 15:13–15); the bird nests of zavot (see Leviticus 15:28–30); the bird nests of women after childbirth (see Leviticus 12:6–8); sin-offerings; and guilt-offerings.” (Sefaria.org translation)

The Gemara immediately asked the obvious question. What is the status of the Kohen? If he is working on behalf of the one who’s bringing the sacrifice, then the priest is benefiting that person by offering up the sacrifice. If he is working on behalf of the Holy One Blessed be He, then the priest isn’t benefiting the one who’s bringing that sacrifice.  “A dilemma was raised before the Sages: Are these priests our agents or agents of Heaven when they perform the Temple service? The Gemara elaborates: What is the practical difference whether they are our agents or God’s agents? The Gemara answers: The difference is with regard to one prohibited by vow from deriving benefit from another. If you say that the priests are our agents, don’t the priests provide benefit for the one for whom benefit is forbidden by vow, and therefore, sacrificing that person’s offering is prohibited? And if you say that they are agents of Heaven, it is permitted. What is the status of priests?” (Sefaria.org translation)

The Gemara on dappim TB Nedarim 35b-36a brings three different case studies to prove whether the Kohen was the agent for the one bringing the sacrifice or was God’s agent. Each proof was deemed insufficient and left the question open.

 Nevertheless, the Ran ד"ה אִיבַּעְיָא לְהוּ: הָנֵי כָּהֲנֵי, שְׁלוּחֵי דִידַן הָווּ, אוֹ שְׁלוּחֵי דִשְׁמַיָּא comments that daf TB Kiddushin 23b once and for all answers our question. To be an agent, the agent and the person who he is an agent for must have the same level of obligations. A good example of this is a prayer leader. A prayer leader must have the same level obligations that the people in the pews have in order to be there agent and fulfill their obligations. If a prayer leader has already prayed the evening service and fulfilled his obligation while the congregation hasn’t, he may not lead the congregation in prayer because they don’t have the same obligations at the very moment. The Kohen and the person bringing the sacrifice never have the same level of obligations. Only a Kohen may offer up sacrifices; a non-Kohen is forbidden to offer up sacrifices. Consequently, they do not have the same level of obligations. From this we can deduce that the Kohen are agents of heaven and the people’s agents.