Leviticus 21:1-3

Rules for the Priests

21:1 The Lord said to Moses: “Say to the priests, the sons of Aaron – say to them, ‘For a dead person no priest is to defile himself among his people, 21:2 except for his close relative who is near to him: his mother, his father, his son, his daughter, his brother, 21:3 and his virgin sister who is near to him, who has no husband; he may defile himself for her.