Numbers 18:7; Numbers 18:20

7 But only you and your sons may serve as priests in connection with everything at the altar and inside the curtain. I am giving you the service of the priesthood as a gift. Anyone else who comes near the sanctuary is to be put to death.”

20 The LORD said to Aaron, “You will have no inheritance in their land, nor will you have any share among them; I am your share and your inheritance among the Israelites.