The structure of the service on Yom Kippur is constructed in such a fashion as to recall, as much as possible, the sevice as it was conducted in the Temple. Thus, everything evolves around the institution of the Këhunna, usually translated “priesthood.” The Torah reading for the day is the story of Nadav and Avihu (Leviticus X), at the very beginning of the institution; and the heart of the Musaf service in the afternoon is the complete accounting of the service as it is conducted when there is a Temple. It therefore seems fitting to explore what a kohén is and how he functions.
Parashath Emor (Leviticus XXI,1-XXIV,23) opens by detailing a number of mitzvoth which a kohén is to observe in order to preserve his unique sanctity among Israel, and summarizes: Vëqiddashto ki eth lechem Elo-heichem hu’ maqriv; qadosh yihye lëcha ki qadosh Ani Ha-Shem (“And you will sanctify him for the sacrifices your G-d’s bread; he will be holy to you for I, Ha-Shem, am holy;” XXI,8).
The sanctity of the kohén is so absolutely essential to Israel’s well-being (indeed to that of the world) that the Rabbis explain the emphasis laid on it by the initial verb in the above verse: “‘and you will sanctify him’ even against his will;” (Yëvamoth 88b). Born into his exalted status as a lineal descendant of Aharon, he can neither run from it nor deny it. And yet our verse strongly implies that his sanctity derives not from some inherent, intrinsic quality inherited from his illustrious ancestor, but rather from his function, “for your G-d’s bread he sacrifices.”
It is on this account that each individual member of the other tribes of Israel (as evidenced by the second-person singular pronouns in our verse) must “treat him in accordance with sanctity,” as Rashi summarizes the Talmud’s conclusion elsewhere (Gittin 59b).
“G-d’s bread?!” The incorporeal, omniscient, omnipotent L-rd of the universe eats food?! What does this really mean?
As has been noted many times by many different authorities, the general purpose of korbanoth is to establish a qurva, a closeness, between Ha-Shem, His nation, and the world. The last is crystal-clear from what we read elsewhere in Leviticus, that sacrificial animals must not have mumim (“blemishes”).
After providing a comprehensive list of conditions which qualify as mumim, the Torah states explicitly: Umiyad ben nochri lo taqrivu eth lechem Elo-heichem mikol élle... (“And from the hand of a foreigner, you will not sacrifice your G-d’s bread from all of these…” XXII,25). That is, foreigners, too, may bring korbanoth, but they must be of equal quality to those brought by Israel.
Korbanoth fall into five categories, of which three have a component which is burnt upon the altar and a component which is eaten by someone (either a kohén or the korban’s owners, depending on the class of korban), and two are burnt up completely on the altar with nothing being eaten. Those latter two are the ‘ola or ishe, so called because it is entirely raised up on the altar (‘ola) and burnt there (ishe, from ésh, “fire”), and the qëtoreth, or “incense.”