These are the sons of Levi, in their kindred and families, leaders in turns, and the number of each of the heads who were doing the works of the ministry of the house of the Lord, from twenty years of age and upward.
and for the divisions of the priests and the Levites: concerning all the works of the house of the Lord and all the items in the ministry of the temple of the Lord.
from thirty years and above, even to fifty years, of all who enter to the office of their ministry and to the service of the covenant of the testimony.