Numbers 8:23 in the King James Version
And the LORD spake unto Moses, saying,
Context
22 After that, the Levites went in to do their service in the Tent of Meeting before Aaron and before his sons: as the LORD had commanded Moses concerning the Levites, so they did to them.
23 The LORD spoke to Moses, saying,
24 “This is what is assigned to the Levites: from twenty-five years old and upward they shall go in to wait on the service in the work of the Tent of Meeting;