(10) But the fat . . . he burnt upon the altar.--The fat portions of this sin offering Aaron was still to burn upon the altar as Moses had done before (see Leviticus 8:14; Leviticus 8:21; Leviticus 8:28), since the miraculous fire from God did not issue forth till the burnt offering of the people was offered. (See Leviticus 9:24)

9:1-21 These many sacrifices, which were all done away by the death of Christ, teach us that our best services need washing in his blood, and that the guilt of our best sacrifices needs to be done away by one more pure and more noble than they. Let us be thankful that we have such a High Priest. The priests had not a day's respite from service allowed. God's spiritual priests have constant work, which the duty of every day requires; they that would give up their account with joy, must redeem time. The glory of God appeared in the sight of the people, and owned what they had done. We are not now to expect such appearances, but God draws nigh to those who draw nigh to him, and the offerings of faith are acceptable to him; though the sacrifices being spiritual, the tokens of the acceptance are spiritual likewise. When Aaron had done all that was to be done about the sacrifices, he lifted up his hands towards the people, and blessed them. Aaron could but crave a blessing, God alone can command it.But the fat, and the kidneys, and the caul above the liver of the sin offering, he burnt upon the altar,.... The Septuagint version is, "he offered them":

as the Lord commanded Moses; see Leviticus 4:8.