Exodus 40:12-15

12Then bring Aaron and his sons to the entrance to the Tent of Meeting and wash them with water. 13And you are to clothe Aaron with the holy garments, anoint him, and consecrate him, so that he may serve Me as a priest. 14Bring his sons forward and clothe them with tunics. 15Anoint them just as you anointed their father, so that they may also serve Me as priests. Their anointing will qualify them for a permanent priesthood throughout their generations.”