Numbers 4:46

These were the sons of Levi after their fathers’ houses, even the heads of the fathers’ houses of those who were counted individually, in the number of names by their polls, who did the work for the service of Yahweh’s house, from twenty years old and upward.

For by the last words of David the sons of Levi were counted, from twenty years old and upward.

“Count the children of Levi by their fathers’ houses, by their families. You shall count every male from a month old and upward.”

The sons of Merari by their families: Mahli and Mushi. These are the families of the Levites according to their fathers’ houses.

from thirty years old and upward even until fifty years old, all who enter into the service to do the work in the Tent of Meeting.

Those who were counted of the sons of Gershon, by their families, and by their fathers’ houses,

Those who were counted of the families of the sons of Merari, by their families, by their fathers’ houses,

“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;

Hezekiah appointed the divisions of the priests and the Levites after their divisions, every man according to his service, both the priests and the Levites, for burnt offerings and for peace offerings, to minister, to give thanks, and to praise in the gates of Yahweh’s camp.

and those who were listed by genealogy of the priests by their fathers’ houses, and the Levites from twenty years old and upward, in their offices by their divisions;

These were those who went up from Tel Melah, Tel Harsha, Cherub, Addan, and Immer; but they could not show their fathers’ houses, and their offspring, whether they were of Israel: