Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Num 8:1-4) The lamps of the sanctuary.
(v. 5-26) Consecration of the Levites, and their service.
Aaron himself lighted the lamps, thus representing his Divine Master. The Scripture is a light shining in a dark place, Pe2 1:19. A dark place even the church would be without it; as the tabernacle, which had no window, would have been without the lamps. The work of ministers is to light these lamps, by expounding and applying the word of God. Jesus Christ is the only Light of our dark, sinful world; and by his atonement, by his word and the Holy Spirit, he diffuses light around.
Here we have directions for the solemn ordination of the Levites. All Israel must know that they took not this honour to themselves, but were called of God to it; nor was it enough that they were distinguished from others. All who are employed for God, must be dedicated to him, according to the employment. Christians must be baptized, ministers must be ordained; we must first give ourselves unto the Lord, and then our services. The Levites must be cleansed. They must be clean that bear the vessels of the Lord. Moses must sprinkle the water of purifying upon them. This signifies the application of the blood of Christ to our souls by faith, that we may be fit to serve the living God. God declares his acceptance of them. All who expect to share in the privileges of the tabernacle, must resolve to do the service of the tabernacle. As, on the one hand, none of God's creatures are his necessary servants, he needs not the service of any of them; so none are merely honorary servants, to do nothing. All whom God owns, he employs; angels themselves have their services.