Exodus 29:8-11

8And thou shalt bring his sons, and put coats upon them. 9And thou shalt gird them with girdles, Aaron and his sons, and bind head-tires on them: and they shall have the priesthood by a perpetual statute: and thou shalt consecrate Aaron and his sons.

10And thou shalt bring the bullock before the tent of meeting: and Aaron and his sons shall lay their hands upon the head of the bullock. 11And thou shalt kill the bullock before Jehovah, at the door of the tent of meeting.