Thematic Bible: Priests prohibited, except for the nearest of kin

Then Yahweh said to Moses, "Speak to the priests, Aaron's sons, and say to them, 'One must not make himself unclean for a dead person among his [own] people, except for his direct relative closest to him: his mother and his father, and his son and his daughter, and his brother, and for his sister, a virgin, [who is] closest to him, {who has not had a husband}--for her he may defile himself. read more.
He must not make himself unclean [as] {a kinsman by marriage}, defiling himself. " 'And they shall not shave bald patches on their head, and they shall not shave off the corner of their beard, and they shall not make a cut in their body. They shall be holy to their God, and they shall not profane the name of their God, because they are bringing near the offerings made by fire to Yahweh--their God's food--and they shall be holy. " 'They shall not {marry} a woman [who is] a prostitute and defiled, nor shall they {marry} a woman divorced from her husband, because each priest [is] holy for his God. And you shall consecrate him, because he is bringing near your God's food; he shall be holy to you, since I, Yahweh, who consecrates you, [am] holy. " 'As for the daughter of any priest, if she is defiled by prostituting, she is disgracing her father--she shall be burned in the fire. " 'As for the priest [who is] higher than his brothers, on whose head the oil of anointment is poured and {he was ordained} to wear the garments, he shall not dishevel his head, and he shall not tear his garments. And he shall not go near any dead person, nor shall he make himself unclean for his father or for his mother.