14 Thus you shall separate the Levites from among the other Israelites, and the Levites shall be mine. 15 Thereafter the Levites may go in to do service at the tent of meeting, once you have cleansed them and presented them as an elevation offering. 16 For they are unreservedly given to me from among the Israelites; I have taken them for myself, in place of all that open the womb, the firstborn of all the Israelites. 17 For all the firstborn among the Israelites are mine, both human and animal. On the day that I struck down all the firstborn in the land of Egypt I consecrated them for myself, 18 but I have taken the Levites in place of all the firstborn among the Israelites. 19 Moreover, I have given the Levites as a gift to Aaron and his sons from among the Israelites, to do the service for the Israelites at the tent of meeting, and to make atonement for the Israelites, in order that there may be no plague among the Israelites for coming too close to the sanctuary.
Matthew Henry's Commentary on Numbers 8:14-19
Commentary on Numbers 8:5-26
(Read Numbers 8:5-26)
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.