Ezra 3:8
And in the second year of their coming unto the house of God in Jerusalem, in the second month, began Zerubbabel, the son of Shealtiel, and Jeshua, the son of Jozadak, and the remnant of their brethren, the priests and the Levites, and all those that were come out of the captivity unto Jerusalem, and appointed the Levites, from twenty years old and upward, to set forward the work of the house of the LORD.
Numbers 4:3
from thirty years old and upward until fifty years old, all that enter into the host, to do work in the tabernacle of the testimony.
1 Chronicles 23:4
Of which, twenty-four thousand were to set forward the work of the house of the LORD, and six thousand were officers and judges;
1 Chronicles 23:24-32
These are the sons of Levi after the houses of their fathers, even the chief of the fathers, as they were counted by number of names by their polls, that did work in the ministry of the house of the LORD, from the age of twenty years and upward.
Ezra 4:3
But Zerubbabel and Jeshua and the rest of the heads of the fathers of Israel, said unto them, Ye have nothing to do with us to build a house unto our God; but we alone will build unto the LORD God of Israel as King Cyrus, the king of Persia, commanded us.