Exodus 40:12-15

“Present Aaron and his sons at the entrance of the Tabernacle, and wash them with water. Dress Aaron with the sacred garments and anoint him, consecrating him to serve me as a priest. Then present his sons and dress them in their tunics. Anoint them as you did their father, so they may also serve me as priests. With their anointing, Aaron’s descendants are set apart for the priesthood forever, from generation to generation.”