Leviticus 9:8

“Aaron therefore went unto the altar, etc.] Of burnt offering, freely and cheerfully, at the direction and introduction of Moses, who acted in this affair in the name of the Lord: and slew the calf of the sin [offering], which [was] for himself; which was to be offered first, as it was proper it should, that, atonement being made for his sins, his after burnt offering might be accepted with God, and he be fit to offer the sacrifices of the people: the calf he slew on the north side of the altar, where all the sin offerings and burnt offerings were slain; (see <030111> Leviticus 1:11 6:25).”

“Aaron . . . went unto the altar, and slew the calf of the sin offering--Whether it had been enjoined the first time, or was unavoidable from the divisions of the priestly labor not being as yet completely arranged, Aaron, assisted by his sons, appears to have slain the victims with his own hands, as well as gone through all the prescribed ritual at the altar.”

“Lev 1:4, Lev 1:5, Lev 4:4, Lev 4:29 Leviticus 9:9”

“Accordingly, he offered first of all the sin-offering and burnt-offering for himself, and then ( Lev 9:15-21) the offerings of the people. The sin-offering always went first, because it served to remove the estrangement of man from the holy God arising from sin, by means of the expiation of the sinner, and to clear away the hindrances to his approach to God. Then followed the burnt-offering, as an expression of the complete surrender of the person expiated to the Lord; and lastly the peace-offering, on the one hand as the utterance of thanksgiving for mercy received, and prayer for its further continuance, and on the other hand, as a seal of covenant fellowship with the Lord in the…”