Leviticus 21:2

1 And the Lord said to Moses, Say to the priests, the sons of Aaron, Let no man make himself unclean for the dead among his people;

2 But only for his near relations, for his mother or his father, his son or his daughter, and his brother;

3 And for his sister, a virgin, for she is his near relation and has had no husband, he may make himself unclean.

4 But let him, being a chief among his people, not make himself unclean in such a way as to put shame on himself.

5 They are not to have their hair cut off for the dead, or the hair on their chins cut short, or make cuts in their flesh.

6 Let them be holy to their God and not make the name of their God common; for the fire offerings of the Lord and the bread of their God are offered by them, and they are to be holy.

7 They may not take as wife a loose or common woman, or one who has been put away by her husband: for the priest is holy to his God.