Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Lev 8:1-13) The consecration of Aaron and his sons.
(v. 14-36) The offerings of consecration.
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, Rev 1:5, Rev 1:6; 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.
In these types we see our great High Priest, even Christ Jesus, solemnly appointed, anointed, and invested with his sacred office, by his own blood, and the influences of his Holy Spirit. He sanctifies the ordinances of religion, to the benefit of his people and the honour of God the Father; who for his sake accepts our worship, though it is polluted with sin. We may also rejoice, that he is a merciful and faithful High Priest, full of compassion to the feeble-minded and tempest-tossed soul. All true Christians are consecrated to be spiritual priests. We should seriously ask ourselves, whether in our daily walk we study to maintain this character? and abound in spiritual sacrifices, acceptable to God through Christ? If so, still there is no cause for boasting. Let us not despise our fellow-sinners; but remembering what we have done, and how we are saved, let us seek and pray for their salvation.