Exodus 29:32

This is the law of the burnt offering, the grain offering and the sin offering and the guilt offering and the ordination offering and the sacrifice of peace offerings,

Then Moses said to Aaron and to his sons, “Boil the flesh at the doorway of the tent of meeting, and eat it there together with the bread which is in the basket of the ordination offering, just as I commanded, saying, ‘Aaron and his sons shall eat it.’

“Have you not driven out the priests of Yahweh, the sons of Aaron and the Levites, and made for yourselves priests like the peoples of other lands? Whoever comes to ordain himself with a bull from the herd and seven rams, even he may become a priest of what are no gods.