Leviticus 21:6-8

They shall be holy to their God and not profane the name of their God; for they present the offerings by fire to the LORD, the food of their God; so they shall be holy. They shall not take [as a wife] a woman who is a prostitute, nor a woman who is divorced from her husband; for the priest is holy to his God. You shall consecrate him, therefore, for he offers the food of your God; he shall be holy to you; for I the LORD, who sanctifies you, am holy.