And after this did Jehoshaphat king of Judah join himself with Ahaziah king of Israel, who did very wickedly:

Wesley's Notes

20:35 After this - This is mentioned as an aggravation of his sin, after so great an obligation laid upon him by God; and after he had been so singularly reproved by a prophet yet he relapsed into the same sin which proceeded partly from that near relation which was contracted between the two families, and partly from the easiness of Jehoshaphat's temper, which could not resist the solicitations of others, in such things as might seem indifferent. For he did not join with him in war, as he did with Ahab, but in a peaceable way only, in a matter of trade and commerce. And yet God reproves and punisheth him for it, ver.37, to shew his great dislike of all familiar conversation of his servants and people with professed enemies of God and of religion, as Ahaziah was. Very wickedly - Or who did industriously, and maliciously, and constantly work wickedness, as the Hebrew phrase implies, giving himself up to idolatry and all wickedness.

Jamieson-Fausset-Brown Bible Commentary

35-37. after this did Jehoshaphat . join himself with Ahaziah . to make ships-A combined fleet was built at Ezion-geber, the destination of which was to voyage to Tartessus, but it was wrecked. Jehoshaphat's motive for entering into this partnership was to secure a free passage through Israel, for the vessels were to be conveyed across the Isthmus of Suez, and to sail to the west of Europe from one of the ports of Palestine on the Mediterranean. Eliezer, a prophet, denounced this unholy alliance, and foretold, as divine judgment, the total wreck of the whole fleet. The consequence was, that although Jehoshaphat broke off-in obedience to the divine will-his league with Ahaziah, he formed a new scheme of a merchant fleet, and Ahaziah wished to be admitted a partner [1Ki 22:48]. The proposal of the Israelitish king was respectfully declined [1Ki 22:49]. The destination of this new fleet was to Ophir, because the Israelitish seaports were not accessible to him for the Tartessus trade; but the ships, when just off the docks, were wrecked in the rocky creek of Ezion-geber.

Matthew Henry's Concise Commentary

20:31-37 Jehoshaphat kept close to the worship of God, and did what he could to keep his people close to it. But after God had done such great things for him, given him not only victory, but wealth; after this, to go and join himself with a wicked king, was very ungrateful. What could he expect but that God would be angry with him? Yet it seems, he took the warning; for when Ahaziah afterward pressed him to join him, he would not, 1Ki 22:49. Thus the alliance was broken, and the Divine rebuke had its effect, at least for a season. Let us be thankful for any losses which may have prevented the loss of our immortal souls. Let us praise the Lord, who sought after us, and left us not to perish in our sins.