Exodus 29:7-9

Amplified Bible

⁷ Then you shall take the anointing oil and pour it on his head and anoint him. ⁸ You shall bring his sons and put tunics on them. ⁹ And you shall wrap them with sashes, Aaron and his sons, and put the [ornamental] caps on them; and the priest’s office shall be theirs by a perpetual statute. So you shall ordain Aaron and his sons.