Leviticus 22:2

Speak unto Aaron and to his sons,.... The priests; the children of Israel or the common people are not mentioned, as having no concern in the following laws about eating holy things:

that they separate themselves from the holy things of the children of Israel; both from offering their lawful sacrifices, which was the business of their office when pure, and chiefly from eating that part of them which was their due, and was allowed them; neither of these they were to do, particularly the latter, when they were in any uncleanness, as the following words show:

and that, they profane not my holy name [in those things] which they hallow unto me; which the children of Israel set apart and devoted to his service; which they would do, by eating their part of them when unclean, and thereby show little reverence to that holy name to which they were devoted; or which the priests themselves sanctified, by offering them to him; for Jarchi says, this takes in the holiness of the priests themselves; but the former seems best, and is confirmed in

Leviticus 22:3:

I [am] the Lord; who is holy himself, and whose holy things these are, and will be sanctified by those that draw nigh unto him.