In the fifth year of Joram the son of Ahab. — See Note on 2 Kings 1:17.
The name Joram is an easy contraction of Jehoram. In this verse and in 2 Kings 8:29 the king of Israel is called Joram, and the king of Judah Jehoram; in 2 Kings 8:21; 2 Kings 8:23-24 Joram is the name of the king of Judah. In 2 Kings 1:17 and 2 Chronicles 22:6, both kings are called Jehoram.
Jehoshaphat being then king of Judah. — Literally, and Jehoshaphat king of Judah; so that the meaning is, “In the fifth year of Joram... and of Jehoshaphat.” Were the reading correct, it would be implied that Jehoram was for some reason or other made king or co-regent in the lifetime of his father, just as Esarhaddon united his heir Assurbanipal with himself in the government of Assyria. But the clause should be omitted as a spurious anticipation of the same words in the next line. So some Hebrew MSS., the Complut., LXX., the Syriac, and Arabic, and many MSS. of the Vulg. The clause as it stands is an unparalleled insertion in a common formula of the compiler, and there is no trace elsewhere of a co-regency of Jehoram with his father. Ewald, after Kimchi, would turn the clause into a sentence, by adding the word mêth, “had died:” “Now Jehoshaphat the king of Judah had died,” an utterly superfluous remark.