Numbers 8:15

And after that shall the Levites go in to do the service of the tabernacle of the congregation: and thou shalt cleanse them, and offer them for an offering.

"After that, the Levites shall go in to do the service of the Tent of Meeting: and you shall cleanse them, and offer them as a wave offering.

And after that shall the Levites go in to do the service of the tent of meeting: and thou shalt cleanse them, and offer them for a wave-offering.

and afterwards do the Levites come in to serve the tent of meeting, and thou hast cleansed them, and hast waved them -- a wave-offering.

After you have cleansed them and presented them as a wave offering, they may come to serve at the Tent of Meeting.