21 And the Levites purified themselves and washed their clothes; then Aaron presented them like a wave offering before the Lord, and Aaron made atonement for them to cleanse them.
22 After that the Levites went in to do their work in the tabernacle of meeting before Aaron and his sons; as the Lord commanded Moses concerning the Levites, so they did to them.
23 Then the Lord spoke to Moses, saying,
24 “This is what pertains to the Levites: From twenty-five years old and above one may enter to perform service in the work of the tabernacle of meeting;
25 and at the age of fifty years they must cease performing this work, and shall work no more.
26 They may minister with their brethren in the tabernacle of meeting, to attend to needs, but they themselves shall do no work. Thus you shall do to the Levites regarding their duties.”