Exodus 29:8-11

8Also you are to bring his sons and put tunics on them.

9You are to gird Aaron and his sons with sashes, tie headwear on them, and they shall hold the priesthood by a perpetual statute. In this way you are to consecrate Aaron and his sons.

10“You are to bring the bull before the Tent of Meeting, and Aaron and his sons are to lay their hands on its head.

11You are to slaughter the bull before Adonai at the entrance of the Tent of Meeting.