22 After that, the Levites came to do their work at the tent of meeting in the presence of Aaron and his sons. So they did to them as the Lord had commanded Moses concerning the Levites.
23 The Lord spoke to Moses:
24 “In regard to the Levites: From 25 years old or more, a man enters the service in the work at the tent of meeting.
25 But at 50 years old he is to retire from his service in the work and no longer serve.
26 He may assist his brothers to fulfill responsibilities at the tent of meeting, but he must not do the work. This is how you are to deal with the Levites regarding their duties.”