Exodus 40:12-16 KJV
And thou shalt bring Aaron and his sons unto the door of the tabernacle of the congregation, and wash them with water. And thou shalt put upon Aaron the holy garments, and anoint him, and sanctify him; that he may minister unto me in the priest's office. And thou shalt bring his sons, and clothe them with coats: and thou shalt anoint them, as thou didst anoint their father, that they may minister unto me in the priest's office: for their anointing shall surely be an everlasting priesthood throughout their generations. Thus did Moses: according to all that the LORD commanded him, so did he.