'Reign' in the Bible

Ishbosheth, Saul's son, was forty years old when he began to reign over Israel, and he reigned two years. But the house of Judah followed David.

Abner said to David, "I will arise and go, and will gather all Israel to my lord the king, that they may make a covenant with you, and that you may reign over all that your soul desires." David sent Abner away; and he went in peace.

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