Numbers 8:21

And the Levites were purified ,.... From sin, by the sprinkling of the sin water, or water of purification on them, Numbers 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 Numbers 8:11 ,

and Aaron made an atonement for them to cleanse them ; by offering the sacrifices for them, Numbers 8:12 .