Thematic Bible: Specially required to avoid

The LORD told Moses, "Speak to the priests, Aaron's sons, and tell them that no priest is to defile himself on account of the dead among his people, except his close relatives his mother, father, son, daughter, brother, or virgin sister (who is a near relative of him and did not have a husband he may defile himself for her). read more.
Because he is a husband among his people, he is not to defile himself, thereby polluting himself. "They are not to cut their hair in ritualistic patterns on their heads, deface the edges of their beards, or make incisions in their flesh. They are to be holy to their God. They are not to defile the name of their God, because they're the ones who bring the offerings of the LORD made by fire the food of their God so they are to be holy.

He is not to come near any dead body whether the deceased is his father or his mother so as not to defile himself. He is not to go out of the sanctuary or defile the sanctuary of his God, because his God's consecrating oil of anointing rests on him. I am the LORD.