The Levites: Ceremonies at Consecration of Making a Sin-Offering For

Then have them take a young bull with its grain offering of fine flour mixed with oil, and you are to take a second young bull for a sin offering.

And the Levites are to lay their hands on the heads of the bulls, and offer to the LORD one as a sin offering and the other as a burnt offering, to make atonement for the Levites.