The Offering of The Whole Burnt Offering (Leviticus 8:18-21).
‘And he presented the ram of the whole burnt-offering, and Aaron and his sons laid their hands on the head of the ram.'
Moses then took the ram of the whole burnt offering, and called on Aaron and his sons to solemnly identify themselves with it by laying their hands on it. Without active participation and genuine response the whole ceremony would have been meaningless.
‘And he killed it, and Moses sprinkled the blood on the altar round about. And he cut the ram into its pieces, and Moses burnt the head, and the pieces, and the fat. And he washed the innards and the legs with water; and Moses burnt the whole ram on the altar: it was a whole burnt-offering for a pleasing odour, it was an offering made by fire to Yahweh; as Yahweh commanded Moses.'
The procedure for the whole burnt offering as described in chapter 1 was now carried through. Aaron slit the ram's throat, and Moses then caught the blood in a basin and sprinkled it on all four sides of the altar. Atonement was to be made for the altar each time an offering was made, atonement which applied to all connected with the offering. The Aaron cut the ram in pieces and Moses burnt all on the altar, the pieces, the head, and the fat. And the innards and legs were washed and they too were burnt on the altar. The whole ram was burned on the altar. It was a whole burnt offering for a pleasing odour. It was an offering made by fire to Yahweh.
So were Aaron and his sons atoned for, and lifted up in dedication to God, in what was a shadow and type of the offering up of Jesus Christ as the perfectly obedient One, the One Whose dedication was total and complete. And so were they accepted for His sake. And we too, if we would serve Him must also be offered up in His dedicatory and atoning offering that we might be totally acceptable to God in His righteousness. We must be united with Him Who said, ‘Lo I come --- to do your will, O God' (Hebrews 10:9). First we come to Him in humility and repentance as our purification for sin offering, and then we come to Him for reconciliation and atonement, that we may fully dedicate ourselves in Him and offer Him as our tribute to God, and offer ourselves in Him (we have nothing else that is worthy to be offered. It is all of grace).