Leviticus
Chapters 21:1-4
Amplified Bible
1THE Lord said to Moses, Speak to the priests [exclusive of the high priest], the sons of Aaron, and say to them that none of them shall defile himself for the dead among his people [by touching a corpse or assisting in preparing it for burial],
2Except for his near [blood] kin, for his mother, father, son, daughter, brother,
3And for his sister, a virgin, who is near to him because she has had no husband; for her he may be defiled.
4He shall not even defile himself, being a [bereaved] husband [his wife not being his blood kin] or being a chief man among his people, and so profane himself.