Leviticus 21:1 WEB

¹  Yahweh said to Moses, 'Speak to the priests, the sons of Aaron, and say to them, 'A priest shall not defile himself for the dead among his people;

²  except for his relatives that are near to him: for his mother, for his father, for his son, for his daughter, for his brother,

³  and for his virgin sister who is near to him, who has had no husband; for her he may defile himself.