Leviticus 21:4

1 Then the LORD said to Moses, “Speak to Aaron’s sons, the priests, and tell them that a priest is not to defile himself for a dead person among his people,

2 except for his immediate family—his mother, father, son, daughter, or brother,

3 or his unmarried sister who is near to him, since she has no husband.

4 He is not to defile himself for those related to him by marriage, and so profane himself.

5 Priests must not make bald spots on their heads, shave off the edges of their beards, or make cuts in their bodies.

6 They must be holy to their God and not profane the name of their God. Because they present to the LORD the offerings made by fire, the food of their God, they must be holy.

7 A priest must not marry a woman defiled by prostitution or divorced by her husband, for the priest is holy to his God.

8 You are to regard him as holy, since he presents the food of your God. He shall be holy to you, because I the LORD am holy—I who set you apart.

Read all of Leviticus 21