269. Even Against His Will: The obligation to sanctify the kohanim
You shall sanctify him… (Leviticus 21:8)
The descendants of Aaron, brother of Moses, are to serve as hereditary priests, called “kohanim” in Hebrew. Because of this, they are given priority in ritual matters. For this reason, a kohein receives the first aliyah when the Torah is read and the kohein has right of first refusal when it comes to bentching (grace after meals).
You will note that the mitzvah is “you shall consecrate him.” The kohein himself has no say in the matter – he is a kohein whether he likes it or not. (Similarly, he can’t modestly forgo the first aliyah in favor of a non-kohein – it’s simply not up to him!) A kohein receives this priority even if he has a blemish that disqualifies him from performing the Temple service. A kohein can, however, forfeit the honor due to him if he is a sinful individual not worthy of it.
The basis of this mitzvah is that God has chosen the kohanim to perform His service. By honoring them, we are honoring Him.
This mitzvah is discussed in the Talmud in tractate Gittin (59b) and elsewhere. It is codified in the Shulchan Aruch in Orach Chaim 135, 167 and 201. (The first of those deals with reading the Torah, while the latter two address the laws of a meal.) This mitzvah is #32 of the 248 positive mitzvos in the Rambam’s Sefer HaMitzvos and #50 of the 77 positive mitzvos that can be fulfilled today in the Chofetz Chaim’s Sefer HaMitzvos HaKatzar.