But they forgot Yahweh their God; and he sold them into the hand of Sisera, captain of the host of Hazor, and into the hand of the Philistines, and into the hand of the king of Moab; and they fought against them.
So you do remember that he started out his career extremely early. As soon as he was weaned he was a public figure. He was there in the place of worship. The people who would gather for worship saw this little boy year by year as he grew and as he developed. They recognized that God's hand was upon this young man. He just sort of naturally grew into the position of leadership and judge over Israel.