John Gill Commentary Leviticus 8

And the Lord spoke to Moses
The following section or paragraph, relating to the consecration of Aaron and his sons, was delivered, according to Jarchi, seven days before the setting up of the tabernacle; but to me it seems to have been delivered after the setting it up, since it was out of the tabernacle that the Lord said all those things recorded in the preceding chapters; and after he had given out the laws concerning sacrifices, then he renewed the order for the consecration of Aaron and his sons, that they might offer them: saying ;
as follows.

Take Aaron, and his sons with him That is, order them to come, or send a message to them, that they appear at such a time at the door of the tabernacle of the congregation, where the ceremony of consecration was to be performed, and was performed, (Leviticus 8:3) which is observed and recorded by Moses, to show that he has a divine warrant for what he did, and that it was not from favour and affection to his brother, and because of the relation he and his family stood in to him, that he invested him and them with the priestly office, but it was by a command from the Lord; nor did Aaron take this honour to himself, but was called of God to it, (Hebrews 5:4) .

and the garments The garments for the priesthood, ordered and described, and now made, see (Exodus 28:1–29:46) and the anointing oil which also was ordered to be made, and now was made, (Exodus 30:23) (37:29) .

and a bullock for the sin offering, and two rams, and a basket of unleavened [bread] which were all to be used at the consecration with the anointing oil Aaron was to be anointed, and also the tabernacle and the altar; and the bullock was to be a sin offering, and one of the rams a burnt offering for Aaron, and his sons, and the other ram was the ram of consecration of them; and out of the basket of unleavened bread one cake of each sort was to be taken, and waved with other things, and burnt, which finished the consecration; but with it was no oath, as in the consecration of the antitypical high priest Christ Jesus, which difference is observed by the apostle, (Hebrews 7:21) see (Exodus 29:1Exodus 29:2) .

And gather you all the congregation together That is, the heads of the tribes and the elders of the people, as Aben Ezra interprets it; for the whole body of the people, and every individual of them, could not be got together: unto the door of the tabernacle of the congregation ; taking this for the whole court itself, as it sometimes is; though no doubt on this occasion as great a number was convened as well could be admitted into the court, or about it, to be spectators and witnesses of the solemn investiture of Aaron and his sons with the priestly office.

And Moses did as the Lord commanded him He convened Aaron and his sons, and the heads of the people, at the door of the tabernacle, and came himself, and brought with him the garments, the oil, and sacrifices, even everything necessary for the consecration: and the assembly was gathered together unto the door of the tabernacle of the congregation ; and this was, according to the Targum of Jonathan, on the twenty third day of the month Adar or February; but it rather seems to be later, some time in the beginning of Nisan or March, and before the passover began, see (Numbers 9:1–5) .

And Moses said to the congregation Having convened them, he opened to them the reason of their being called together, which was not done of himself, but by divine direction: this [is] the thing which the Lord commanded to be done; namely, what follows, concerning the consecration of Aaron and his sons to be priests, and the investiture of them with that office, attended with various rites and ceremonies to be performed, of which they were to be witnesses.