Leviticus 9:1-7

And it came to pass on the eighth day, that Moses called Aaron and his sons, and the elders of Israel; and he said unto Aaron, Take thee a young calf for a sin offering, and a ram for a burnt offering, without blemish, and offer them before the LORD. And unto the children of Israel thou shalt speak, saying, Take ye a kid of the goats for a sin offering; and a calf and a lamb, both of the first year, without blemish, for a burnt offering; also a bullock and a ram for peace offerings, to sacrifice before the LORD; and a meat offering mingled with oil: for to day the LORD will appear unto you. And they brought that which Moses commanded before the tabernacle of the congregation: and all the congregation drew near and stood before the LORD. And Moses said, This is the thing which the LORD commanded that ye should do: and the glory of the LORD shall appear unto you. And Moses said unto Aaron, Go unto the altar, and offer thy sin offering, and thy burnt offering, and make an atonement for thyself, and for the people: and offer the offering of the people, and make an atonement for them; as the LORD commanded.