Exodus 40:12-15

12And thou shalt bring Aaron and his sons to the door of the tabernacle of the congregation, and wash them with water. 13And thou shalt put upon Aaron the holy garments, and anoint him, and sanctify him; that he may minister to me in the priest’s office. 14And thou shalt bring his sons, and clothe them with coats: 15And thou shalt anoint them, as thou didst anoint their father, that they may minister to me in the priest’s office: for their anointing shall surely be an everlasting priesthood throughout their generations.