(16) Instead of such as open every womb, even instead of the firstborn of all the children of Israel.—It is difficult to determine whether the second clause is to be regarded as an exact equivalent, or as a limitation of the first. If an exact equivalent, a different meaning must be assigned to the firstborn from that which it commonly bears in the Pentateuch, where it appears to be restricted to the firstborn son on the father’s side. (Cf. Exodus 13:2.)

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.Offer ... offering - Compare the margin Aaron pointed to the Levites, and then waved his hands, indicating (compare Leviticus 7:30 note) that the offering was dedicated to God, and, again, by grant from Him, withdrawn for the use of the priests.15. after that, shall the Levites go in to do the service of the tabernacle of the congregation—into the court, to assist the priests; and at removal into the tabernacle—that is, into the door of it—to receive the covered furniture. They are given unto me by the people’s consent, as well as taken (as it follows) by my choice and command. See Numbers 3:9.

For they are wholly given unto me from among the children of Israel,.... All of them, entirely, and most certainly; or, "given, given" (u), which is repeated for the confirmation of it; or because of their being twice given, first to the Lord by the children of Israel, and then by the Lord to Aaron and his sons, as Chaskuni; though Jarchi interprets it of the different parts of their service they were devoted to, given for bearing and carrying the vessels of the sanctuary, and given for the song, or to be singers in the temple:

instead of such as open, every womb, even instead of the firstborn of all the children of Israel have I taken them unto me; See Gill on Numbers 3:12, and See Gill on Numbers 3:13.

(u) "dati, dati", Pagninus, Montanus, Vatablus; so Drusius and Ainsworth.

For they are wholly given unto me from among the children of Israel; instead of such as open every womb, even instead of the firstborn of all the children of Israel, have I taken them unto me.