Ezra 3:8
Now in the second year of their coming to God's house at Jerusalem, in the second month, Zerubbabel the son of Shealtiel, and Jeshua the son of Jozadak, and the rest of their brothers the priests and the Levites, and all those who had come out of the captivity to Jerusalem, began the work and appointed the Levites, from twenty years old and upward, to have the oversight of the work of the LORD's house.
Numbers 4:3
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.
1 Chronicles 23:4
David said, "Of these, twenty-four thousand were to oversee the work of the house of the LORD; six thousand were officers and judges;
1 Chronicles 23:24-32
These were the sons of Levi after their fathers' houses, even the heads of ancestral houses of those who were counted individually, in the number of names by their polls, who did the work for the service of the house of the LORD, from twenty years old and upward.
Ezra 4:3
But Zerubbabel, and Jeshua, and the rest of the heads of ancestral houses of Israel, said to them, "You have nothing to do with us in building a house to our God; but we ourselves together will build to the LORD, the God of Israel, as king Cyrus the king of Persia has commanded us."