Exodus 29:8-11

8And thou shalt bring his sons near, and clothe them with the vests.

9And thou shalt gird them with the girdle — Aaron and his sons, and bind the high caps on them; and the priesthood shall be theirs for an everlasting statute; and thou shalt consecrate Aaron and his sons.

10And thou shalt present 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 slaughter the bullock before Jehovah, at the entrance of the tent of meeting;