They shall be holy to their God and not profane the name of their God, for they offer the offerings of the LORD made by fire, and the bread of their God; therefore they shall be holy.
Leviticus 21:6
Surrounding context
21:5 "They shall not make any bald place on their heads, nor shall they shave the edges of their beards nor make any cuttings in their flesh.
21:6 They shall be holy to their God and not profane the name of their God, for they offer the offerings of the LORD made by fire, and the bread of their God; therefore they shall be holy.
21:7 They shall not take a wife who is a harlot or a defiled woman, nor shall they take a woman divorced from her husband; for the priest is holy to his God.