Leviticus 21:1-6 RSVA

1 And the LORD said to Moses, "Speak to the priests, the sons of Aaron, and say to them that none of them shall defile himself for the dead among his people,
2 except for his nearest of kin, his mother, his father, his son, his daughter, his brother,
3 or his virgin sister (who is near to him because she has had no husband; for her he may defile himself).
4 He shall not defile himself as a husband among his people and so profane himself.
5 They shall not make tonsures upon their heads, nor shave off the edges of their beards, nor make any cuttings in their flesh.
6 They shall be holy to their God, and not profane the name of their God; for they offer the offerings by fire to the LORD, the bread of their God; therefore they shall be holy.