Thus did Moses and Aaron and all the congregation of the people of Israel to the Levites. According to all that the LORD commanded Moses concerning the Levites, the people of Israel did to them.
20. And Moses, and Aaron, and all the congregation The Levites also are now inaugurated for the performance of their duties, but in their proper order, because their condition was inferior. Here it must be noted that the sons of Moses and their descendants were placed in this lower rank, and excluded from all expectation of the priesthood.
We read before of the separating of the Levites from among the children of Israel when they were numbered, and the numbering of them by themselves (Num 3:6, Num 3:15), that they might be employed in the service of the tabernacle. Now here we have directions given for their solemn ordination (Num 8:6), and the performance of it, Num 8:20.
Commenting on Numbers 8:5-26
And the Levites were purified,.... From sin, by the sprinkling of the sin water, or water of purification on them, Num 8:7, and they washed their clothes; that they might have no defilement about them, neither in their bodies, nor in their garments: and Aaron offered them as an offering before the Lord; a wave offering, as in Num 8:11, and Aaron made an atonement...