Ezra 3:8
Now in the second year of their coming unto the house of God at Jerusalem, in the second month, began Zerubbabel the son of Shealtiel, and Jeshua the son of Jozadak, and the rest of their brethren the priests and the Levites, and all they that were come out of the captivity unto Jerusalem, and appointed the Levites, from twenty years old and upward, to have the oversight of the work of the house of Jehovah.
Numbers 4:3
from thirty years old and upward even until fifty years old, all that enter upon the service, to do the work in the tent of meeting.
1 Chronicles 23:4
Of these, twenty and four thousand were to oversee the work of the house of Jehovah; and 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 the fathers houses of those of them that were counted, in the number of names by their polls, who did the work for the service of the house of Jehovah, from twenty years old and upward.
Ezra 4:3
But Zerubbabel, and Jeshua, and the rest of the heads of fathers houses of Israel, said unto them, Ye have nothing to do with us in building a house unto our God; but we ourselves together will build unto Jehovah, the God of Israel, as king Cyrus the king of Persia hath commanded us.