Numbers 9:6

9:6 It happened that some men who were ceremonially defiled by the dead body of a man could not keep the Passover on that day, so they came before Moses and before Aaron on that day.

Leviticus 21:1-2

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,

Leviticus 21:10-12

Rules for the High Priest

21:10 “‘The high priest – who is greater than his brothers, on whose head the anointing oil is poured, who has been ordained to wear the priestly garments – must neither dishevel the hair of his head nor tear his garments. 21:11 He must not go where there is any dead person; he must not defile himself even for his father and his mother. 21:12 He must not go out from the sanctuary and must not profane the sanctuary of his God, because the dedication of the anointing oil of his God is on him. I am the Lord.

Ezekiel 44:25

44:25 “‘They must not come near a dead person or they will be defiled; however, for father, mother, son, daughter, brother or sister, they may defile themselves.