And Moses said unto 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.

When the congregation was assembled, Moses said, "This is the word which Jehovah commanded you to do." His meaning was, the substance or essential part of the instructions in Exodus 28:1 and Exodus 29:1-37, which he had published to the assembled congregation before the commencement of the act of consecration, and which are not repeated here as being already known from those chapters. The congregation had been summoned to perform this act, because Aaron and his sons were to be consecrated as priests for them, as standing mediators between them and the Lord.

And Moses said unto the congregation, This is the thing which the LORD commanded to be done.

8:1-13 The consecration of Aaron and his sons had been delayed until the tabernacle had been prepared, and the laws of the sacrifices given. Aaron and his sons were washed with water, to signify that they ought to purify themselves from all sinful dispositions, and ever after to keep themselves pure. Christ washes those from their sins in his own blood whom he makes kings and priests to our God, Re 1:5,6; and those that draw near to God must be washed in pure water, Heb 10:22. The anointing of Aaron was to typify the anointing of Christ with the Spirit, which was not given by measure to him. All believers have received the anointing.