In this chapter, Jehoshaphat allies with the king of Israel to attack Aram.
Unlike the previous chapter, the narrative for this chapter closely mirrors the text from the book of Kings, 1 Kings 22 to be precise. We've been tracking the similarities and differences between Kings and Chronicles for quite some time now. For a long time, the text was very similar, especially during the lifetimes of David and Solomon who would have been of interest to both the northern and southern kingdoms. The texts started to diverge more broadly with Rehoboam and Asa, and now during the lifetime of Jehoshaphat the texts diverge even more. In particular, nearly all of the material from 1 Kings 15-21 is omitted from Chronicles. These chapters deal with the succession of kings of Israel and then the stories of Ahab's conflict with Elijah and several foreign invasions. None of this is considered "of interest" to the southern kingdom, so it is left out of Chronicles.
This chapter marks a brief convergence between the two texts, because this story is of interest to both the northern and southern kingdoms. It is a story about Ahab and his war against Aram, but it is also an important story from Jehoshaphat's reign. In keeping with the intention of the Chronicler, I'm going to mostly focus on what this story tells us about Jehoshaphat and the history of Judah. For more on how this story plays into Ahab's life and reign, see my commentary on 1 Kings 22.
In broad terms, I think a lot of this chapter is centered around the relationship between Judah and Israel, contrasting the righteous king Jehoshaphat against the idolatrous king Ahab.
Beginning in verses 1-3, we can see that things are looking good for Judah. Jehoshaphat, who in the previous chapter instituted religious reforms and received blessings from God, is now negotiating peace with Ahab by intermarriage. I think this is a good moment for me to briefly recap the history of conflict between Israel and Judah. In the beginning, these two kingdoms were divided when the northern tribes followed Jeroboam and the southern two tribes of Judah and Benjamin stayed with Rehoboam, the son of Solomon. Jeroboam quickly constructed idols in order to keep the people from going to the temple in Jerusalem, and this created a religious fracture between the two kingdoms. While both the northern and southern kingdoms had high places and Asherah poles, the northern kingdom went much further into idolatry while the southern kingdom stayed relatively close to temple worship and the LORD. The history of the kings we've read about has roughly sustained this point, with Abijah, Asa and now Jehoshaphat all commended for being godly rulers sometimes (in spite of their sins at other times).
On the other hand, if you read the narrative in Kings you will see that numerous kings of Israel are lambasted for being evil, ungodly men, including Nadab, Baasha, Elah, Zimri, Omri and concluding with Ahab, who is considered the worst of the whole bunch. It's basically the whole list of kings from Jeroboam all the way down to Ahab.
There are also numerous military conflicts between these two nations, with Abijah (king of Judah) fighting and winning a battle against Israel, and Asa (another king of Judah) negotiating a treaty with Aram in order to drive back and defeat Israel. Now that Judah and Israel are drawing together an alliance, the first question in my mind is whether or not this is appropriate for Judah to do. On the one hand, I would certainly imagine the LORD wishes there to be some kind of reconciliation between the twelve tribes. On the other hand, we have every indication (greatly reinforced in this chapter) that the northern kingdom is still in the grips of idolatry and sin, and frankly, it just doesn't seem like reconciliation is possible at this point in history.
As a guidance point, let us recall the Law of Moses. It thoroughly commanded Israel to stay separate and apart from the idolatrous nations that inhabited the promised land before their arrival. The Pentateuch warned the Israelites over and over that intermarriage or alliances with the native peoples would be a "thorn in the side" of Israel (Num 33:55-56), a perpetual hindrance, and that these peoples would teach the Israelites to sin and in so doing, condemn Israel to the same destruction that the Israelites were supposed to bring to the people they were displacing. The military code in Deuteronomy 20 makes it clear that any of the nations in the promised land must be wholly destroyed or else they will cause Israel to stumble and fall (Deut 20:16-18).
With that in mind, while I don't think Judah has a mandate to destroy the northern kingdom, I think one could reasonably argue that they should try to maintain the same separation with the northern kingdom that they would have with any other idolatrous nation.
So that is the context for what is happening in this chapter. Regardless of what stance Judah should take regarding her sinful neighbor, I hope my readers understand the implied peril of Jehoshaphat's overture to Ahab, because he is risking the influence and culture of the northern kingdom dragging down Judah into the same kinds of problems that have afflicted Israel for years.
The middle part of this chapter (verses 4-27) is a striking demonstration of the differences that still remained between the northern kingdom and southern kingdom, in spite of their erstwhile alliance. In terms of the fundamental question, "how do we make decisions?", Ahab listens to the prophets of Baal, while Jehoshaphat seeks a prophet of the LORD. It's funny, you might not realize they are prophets of Baal from this chapter. In verse 4, Jehoshaphat says, "can you bring a prophet of the LORD?" Ahab is all like, "yeah, sure thing", and he hauls over these 400 guys. They prophesy that God will bring them victory, and then Jehoshaphat responds with, "no seriously guys, can you find an ACTUAL prophet of the LORD here?". Ahab says, "well... I suppose we have this one guy, but I don't like him." In verses 10-11, the 400 dudes are still going strong, and they literally prophesy in the name of the LORD, even though we have already pretty much established they are not prophets of the LORD based on the exchange in v. 6-7.
After all that, Jehoshaphat insists on hearing from a real prophet of the LORD, Micaiah comes and does his thing (telling Ahab he's gonna die), and weirdly enough, Jehoshaphat ends up going along with the battle anyway (v. 28). You'd figure after being so insistent upon hearing from a prophet of the LORD, Jehoshaphat would maybe listen to what he has to say, but instead it looks like Jehoshaphat felt pressured into going along with Ahab because of their political agreement. This is exactly the danger that I was talking about from Numbers and Deuteronomy. Because Jehoshaphat allied himself with Ahab, he tied his own fate to the fate of Ahab and the complete destruction of Ahab became the partial destruction of Jehoshaphat. Jehoshaphat survived, but much of his army was killed in the defeat.
What I take from this chapter is that Jehoshaphat is a man who is trying to do the right thing, insisting on following the LORD and bringing in a real prophet, and then... failing miserably. He should have never been here. I don't know why he made an alliance with Ahab, but it was the wrong decision and it eventually led him to this place, where he felt compelling to go along with Ahab's plan even when the prophet that he insisted to hear is telling him otherwise.
I think from this story, we can get a sense that while Jehoshaphat is honored by Ahab, Ahab is the person who controls this alliance. Ahab is the man with the plan, and Jehoshaphat is just following along. The prophets of Baal are more numerous and more forceful than the prophet of the LORD, and from the prior confrontations we get the sense that Israel has more military strength than Judah. Once again, being in a position where an idolatrous king can bully you into doing what he wants is a terrible strategic decision by Jehoshaphat, because it separates him from obeying the LORD which is the only way Judah could ever be victorious.
In the end, the LORD spares Jehoshaphat's life when the king cries out to God (v. 31), which shows that even while fighting alongside Ahab, Jehoshaphat still had his heart set upon the LORD.
In the next chapter, this story concludes when a prophet rebukes Jehoshaphat for his partnership with Ahab.