'Twenty' in the Bible

Now in the second year of their coming to the house of God at Jerusalem in the second month, Zerubbabel the son of Shealtiel and Jeshua the son of Jozadak and the rest of their brothers the priests and the Levites, and all who came from the captivity to Jerusalem, began the work and appointed the Levites from twenty years and older to oversee the work of the house of the Lord.