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