2 Kings 8:16
And in the fifth year of Joram the son of Ahab king of Israel, Jehoshaphat being then king of Judah, Jehoram the son of Jehoshaphat king of Judah began to reign.
And in the fifth year of Joram the son of Ahab king of Israel,.... Who began his reign in the eighteenth year of Jehoshaphat, 2 Kings 3:1.
Jehoshaphat being then king of Judah; as he continued to be two years more; for this must be in the twenty third year of his reign, and he reigned twenty five years, 1 Kings 22:42.
Jehoram the son of Jehoshaphat king of Judah began to reign; according to Dr. Lightfoot {h}, there were three beginnings of his reign; "first", when his father went with Ahab to Ramothgilead, when be was left viceroy, and afterwards his father reassumed the kingdom; the "second" time was, when Jehoshaphat went with the kings of Israel and Edom against Moab; and this is the time here respected, which was in the fifth of Joram king of Israel; and the "third" time was, at the death of his father; but knew his father was living.
{h} Works, vol. 1. p. 84.