The Levites could only undertake their duties Numbers 3:44-51.
The distinction between the “consecration” of the priests Numbers 8:21 of the Levites is marked. These rites of purification are similar to those incumbent on the priests of Egypt.
Numbers 8:7
Water of purifying - literally, “sin water:” i. e. water to cleanse from sin; no doubt taken from the laver of the sanctuary, which was used by the priests for purification before they went into the tabernacle to minister (compare Numbers 5:17; Exodus 30:18 ff).
The “sprinkling” of so large a body of men could have been only general, but tokens of individual purification are specified (compare also Leviticus 14:8).
Numbers 8:8
The two bullocks were “to make an atonement for the Levites,” and therefore are presented in their name. These offerings are similar to those prescribed in Leviticus 8:14 ff at the consecration of the priests, except that the burnt-offering was on that occasion a ram. The larger victim corresponds to the larger number of the Levites.
Numbers 8:10
The children of Israel - i. e. through the heads of their tribes, who Numbers 7:2 no doubt acted for their tribesmen. This act, the distinguishing feature of the ceremony, represented the transfer to the Levites of the sacred duties originally incumbent on the whole people.
Numbers 8:11
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hands, indicating (compare Leviticus 7:30 note) that the offering was dedicated to God, and, again, by grant from Him, withdrawn for the use of the priests.
Numbers 8:19
Make an atonement for the children of Israel - i. e. by performing those services which were due from the children of Israel; the omission of which by the children of Israel would, but for the interposition of the Levites, have called down “wrath” from God, or Numbers 1:53 “plague.” The institution of the Levites was an extension of that mediatorial system which the people themselves, terrified at the direct manifestations to them of the divine presence, desired; see Deuteronomy 5:25. Further, it is suggested to us here as an act of mercy on the part of God; yet even the priests and Levites themselves were not always sufficiently heedful and reverent. Compare Numbers 17:10; Leviticus 10:1 ff; 2 Samuel 6:6 following.
Numbers 8:21
Were purified - Rather, purified themselves; as directed in Numbers 8:7.