'Twenty' in the Bible

After twenty years, during which Solomon built the Lord's temple and his royal palace,

Amaziah assembled the people of Judah and assigned them by families to the commanders of units of a thousand and the commanders of units of a hundred for all Judah and Benjamin. He counted those twenty years old and up and discovered there were 300,000 young men of fighting age equipped with spears and shields.

Ahaz was twenty years old when he began to reign, and he reigned for sixteen years in Jerusalem. He did not do what pleased the Lord, in contrast to his ancestor David.

They made disbursements to the priests listed in the genealogical records by their families, and to the Levites twenty years old and up, according to their duties as assigned to their divisions,