Charles Ellicott Commentary 2 Chronicles 18:34

"And the battle increased that day: howbeit the king of Israel stayed himself up in his chariot against the Syrians until the even; and about the time of the going down of the sun he died." — 2 Chronicles 18:34 (ASV)

Increased. —Literally, went up, grew. (Amos 7:0, concerning the growth of grass.)

However, the king of Israel held himself up in his chariot. —Literally, and the king of Israel was (or, continued) holding himself up in the chariot, facing Aram, until the evening. 1 Kings 22:35 reads: was held up in the chariot, etc., and he died in the evening.

The reading of Chronicles is preferable, the sense being that Ahab bravely bore up against the pain of his wound, in order not to discourage his own side by retiring from the field. The rest of the narrative, which tells of the return of the army and the washing of Ahab’s chariot at the pool of Samaria (1 Kings 22:36–38), is omitted here because Jehoshaphat was not concerned in it, and perhaps because the chronicler had a true perception of the real climax of this vivid story of ancient times.