Ezra 3:8

And in the second year to their coming to the house of God at Jerusalem, in the second month, began Zerubbabel son of Shealtiel, and Joshua son of Josedek, and the remainder of their brethren the priests, and the Levites, and all those coming from the captivity to Jerusalem; and they will cause the Levites to stand up, from the son of twenty years and above, to superintend over the works of the house of Jehovah.

Numbers 4:3

From the son of thirty years and above, and to the son of fifty years, all coming in to war to do the works of the tent of appointment

1 Chronicles 23:4

From these to superintend over the work of the house of Jehovah, twenty and four thousand; and scribes and judges, six thousand:

1 Chronicles 23:24-32

These the sons of Levi for the house of their fathers: the heads of the fathers for their reviewing by the number of names to their craniums doing the work for the service of the house of Jehovah, from the son of twenty years and above.

Ezra 4:3

And to them Zerubbabel will say, and Joshua, and the rest of the heads of the fathers to Israel, Not to you and to us to build a house to our God; for we together will build to Jehovah God of Israel, as the king Cyrus king of Persia commanded us.

Treasury of Scripture Knowledge

Summary

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 remnant 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 set forward the work of the house of the LORD.

Twenty years old

Bible References

Twenty years old

Numbers 4:3
From the son of thirty years and above, and to the son of fifty years, all coming in to war to do the works of the tent of appointment
1 Chronicles 23:24
These the sons of Levi for the house of their fathers: the heads of the fathers for their reviewing by the number of names to their craniums doing the work for the service of the house of Jehovah, from the son of twenty years and above.