Now Jehoshaphat had great riches and honor, and he made a marriage alliance with Ahab.
Here is, I. Jehoshaphat growing greater. It was said before (Ch2 17:5) that he had riches and honour in abundance; and here it is said again that his wealth and honour increased upon him by piety and good management. II. Not growing wiser, else he would not have joined with Ahab, that degenerate Israelite, who had sold himself to work wickedness.
Commenting on 2 Chronicles 18:1-3
Now Jehoshaphat had riches and honour in abundance, and joined affinity with Ahab. (a) For Joram Jehoshaphat's son married Ahab's daughter.
Jehoshaphat had riches and honor - The preceding chapter gives ample proof of this. Joined affinity with Ahab - Took his daughter Athalia to be wife to his son Joram.