'Twenty' in the Bible

In the second year after they had come to the temple of God in Jerusalem, in the second month, Zerubbabel the son of Shealtiel and Jeshua the son of Jozadak initiated the work, along with the rest of their associates, the priests and the Levites, and all those who were coming to Jerusalem from the exile. They appointed the Levites who were at least twenty years old to take charge of the work on the Lord's temple.