2 Kings 13:10

In the thirty and seventh year of Joash, king of Judah, &c. A difficulty arises in comparing this with 2 Kings 13:1, where it is said, Jehoahaz began to reign in the twenty-third year of Joash, king of Judah, and reigned seventeen years: from whence it follows, that this Jehoash, son of Jehoahaz, began to reign, not in the thirty-seventh, but in the thirty-ninth or fortieth year of Joash, king of Judah. This difficulty, however, is solved by supposing, what is very probable, that Jehoahaz had made his son Jehoash king, jointly with himself, two or three years before his death. This is the more probable, because he was perpetually in a state of war, and consequently in danger of an untimely death; and because his son was a man of valour, as is implied, 2 Kings 13:12, and declared, 2 Chronicles 25:17.