Leviticus 21:11-13

¹¹neither shall he go in to any dead body, neither shall he defile himself for his father or his mother.

¹²And he shall not go forth out of the sanctuary, and he shall not profane the sanctuary of his God, because the holy anointing oil of God is upon him: I am the Lord.

¹³He shall take for a wife a virgin of his own tribe.