Exodus 29:4-9

Then you shall bring Aaron and his sons to the doorway of the tent of meeting and wash them with water. You shall take the garments, and put on Aaron the tunic and the robe of the ephod and the ephod and the breastpiece, and gird him with the skillfully woven band of the ephod; and you shall set the turban on his head and put the holy crown on the turban. Then you shall take the anointing oil and pour it on his head and anoint him. You shall bring his sons and put tunics on them. You shall gird them with sashes, Aaron and his sons, and bind caps on them, and they shall have the priesthood by a perpetual statute. So you shall ordain Aaron and his sons.