Ezra 3:8 NKJV

[8] Now in the second month of the second year of their coming to the house of God at Jerusalem, Zerubbabel the son of Shealtiel, Jeshua the son of Jozadak, and the rest of their brethren the priests and the Levites, and all those who had come out of the captivity to Jerusalem, began work and appointed the Levites from twenty years old and above to oversee the work of the house of the LORD.