(41) Jehoshaphat.--The narrative here, so far as it is full and continuous, centres round the prophetic work of Elijah and Elisha, the scene of which was in Israel; and the compiler contents himself with the insertion of a few brief annalistic notices of the kingdom of Judah, taking up the thread of the narrative of chapter 15:24, except where (as in 2 Kings 3) it becomes again connected with the history of Israel. In the Chronicles, on the contrary, there is a full and interesting account of the reign of Jehoshaphat, and especially of his great religious revival (2 Chronicles 17-20), coinciding with this chapter, almost verbally, in the account of the battle at Ramoth-gilead. The brief notices here of the religious work of Jehoshaphat, his "might," and his "wars," agree entirely with this fuller record.
Verse 41. - And Jehoahaphat ["Whom Jehovah judges"] the son of Asa began to reign over Judah in the fourth year of Ahab king of Israel. [The historian now resumes for a moment the history of Judah, which has dropped out of notice since 1 Kings 15:24, where the accession of Jehoshaphat was mentioned. His reign, which is here described in the briefest possible way, occupies four chapters (17-20.) of 2 Chronicles]
And Jehoshaphat the son of Asa began to reign over Judah in the fourth year of Ahab king of Israel. And as Ahab reigned twenty two years, 1 Kings 16:29, Jehoshaphat must reign about eighteen years with him, and seven years after him.