And Moses brought Aaron and his sons and washed them with water.
God had given Moses orders to consecrate Aaron and his sons to the priests' office, when he was with him the first time upon mount Sinai, Ex. 28 and Exo 29:1, where we have also the particular instructions he had how to do it. Now here we have, I. The orders repeated. What was there commanded to be done is here commanded to be done now, Lev 8:2, Lev 8:3.
Commenting on Leviticus 8:1-13
And Moses brought Aaron and his sons,.... To the laver which was in the court of the tabernacle and washed them with water; to show that they should be clean that bear the vessels of the Lord, and offer the sacrifices of the people; all that are in public office in the house of God ought to have both clean hands and a pure heart...
Moses . . . washed them with water--At consecration they were subjected to entire ablution, though on ordinary occasions they were required, before entering on their duties, only to wash their hands and feet. This symbolical ablution was designed to teach them the necessity of inward purity, and the imperative obligation on those who bore the vessels and conducted the services of the sanctuary to be holy.