'Thirty' in the Bible

David was thirty years old when he began to reign and he reigned for forty years.

David again assembled all the best men in Israel, thirty thousand in number.

At the time of the harvest three of the thirty leaders went down to David at the cave of Adullam. A band of Philistines was camped in the valley of Rephaim.

He received honor from the thirty warriors, though he was not one of the three elite warriors. David put him in charge of his bodyguard.

Included with the thirty were the following: Asahel the brother of Joab, Elhanan son of Dodo from Bethlehem,