1 And it came to pass on the eighth day, that Moses called Aaron and his sons, and the elders of Israel;
2 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.
3 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;
4 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.
For seven days, Aaron had watched Moses performing the rituals and sacrifices of the tabernacle, but now it is a new week, a new beginning. and Aaron is going to start performing in his office as the high priest now. And then, after Aaron has performed his duties as the high priest, his sons, the regular priests, will began functioning in their roles also. From God to Moses to Aaron to his sons. From God to prophet to family patriarch to children. This is the pattern that is established.
But who was Aaron to perform the ritual for? Two parties, actually. In verse 2, we learn he is to bring offerings for himself and in verse 3 we learn he is to receive offerings from all of Israel. This establishes another important principle of the patriarchal order mentioned above: it is not merely about the downward flow of power and authority, but the upward flow of guilt and responsibility for sin. Indeed, the former only comes hand-in-hand with the latter. There is no authority without burden. The authority is for the addressing of that burden.
Aaron was being called to be the father of Israel, and that meant that in addition to managing his own sanctity before the Lord, he must manage that of all the children also. Paul made this same notion very clear when he compared the responsibility of husbands to that of Christ in Ephesians 5. Of course, none of this is meant to deny the free will of those who are under the patriarch. The Israelites could choose not to bring their offerings to the tabernacle, and the wife and children can choose not to follow the counsel of the father, and grace must be accounted for those fathers and high priests who can answer a full tally to the Lord. None of that changes the pattern that God has established for authority and responsibility, though. Once again, it is a loop that finds Christ at each end. The authority flows down from Christ, and the responsibility comes back up to him. He will ultimately answer for any missing souls, and he will empower the rescue of all that are willing to be found.