Exodus 40:12-15

“Finally, bring Aaron and his sons to the entrance of the Tent of Meeting and wash them with water. Dress Aaron in the sacred vestments. Anoint him. Set him apart to serve me as priest. Bring his sons and put tunics on them. Anoint them, just as you anointed their father, to serve me as priests. Their anointing will bring them into a perpetual priesthood, down through the generations.”