David was thirty years old when he began to reign At this age the Levites were at first appointed to begin their ministrations, Numbers 4:3. About this age the Son of David entered upon his public ministry, Luke 3:23. And it is the age when men come to their full maturity of strength and judgment. In Jerusalem he reigned thirty and three years By this it appears it was immediately after his third unction that he made the attempt upon Jerusalem, mentioned in the next verse, otherwise he could not have reigned there so long.
Related Commentaries of 2 Samuel 5:4
2 Samuel 5:4-5
4 David was thirty years old when he began to reign, and he reigned forty years.
5 In Hebron he reigned over Judah seven years and six months: and in Jerusalem he reigned thirty and three years over all Israel and Judah.