Exodus 29:8-11

8You shall bring his sons and put 1tunics on them. 9You shall gird them with 2sashes, Aaron and his sons, and bind 3caps on them, and they shall have 4the priesthood by a perpetual statute. So you shall 56ordain Aaron and his sons.

10“Then you shall bring the bull before the tent of meeting, and Aaron and his sons shall 7lay their hands on the head of the bull. 11You shall slaughter the bull before the Lord at the doorway of the tent of meeting.