Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
The following commentary covers Chapters 17 through 20.
Jehoshaphat, his son succeeds him, and begins his reign by walking faithfully with God. He strengthened his kingdom against Israel, an enemy more dangerous by their example than by their strength. When anything pretends to be in connection with God and to acknowledge Him, there is no safety except in judging it with a spiritual judgmentwhich can only be formed through a just sense of God's honor-making no terms with that which pretends to be connected with Him, and treating it as an enemy. This is what Jehoshaphat did at first; and, as he did not walk in the ways of Israel, Jehovah established the kingdom in his hand. Blessed of Jehovah, he takes away the high places and the groves, and seeks with much faithfulness and zeal to instruct the people in the true knowledge of the Lord; Jehovah preserves him from war, and some of the nations even become tributary to him on account of his power.
In many respects this is a more beautiful picture than anything we have yet read in the history of the kings. But this prosperity becomes a snare to him; and it bore most bitter fruits when his real piety was not present as a counterpoise.
The prosperity with which God had blessed him in consequence of his faithfulness made it worth while to seek alliance with him, and rendered it more difficult to attack him. Thus at ease, Jehoshaphat on his part joins affinity with Israel. His prosperity put him in a condition to do so in a manner which made the alliance honorable. The human heart, when it is not kept by God, can act generously with respect to the evil which it fears not; but this is not charity. Outwardly Jehoshaphat is faithful to Jehovah, but the wrath of Jehovah is upon him.
Nevertheless, when he had returned to his house, the king sets himself to bring back the people to the fear of Jehovah, and to cause judgment and righteousness to be executed in Israel. But war begins. He could no longer have the unmingled blessing of having to do with God alone without trial. The intervention of the enemy was now needful for his good, according to God's government, although in the trial through which he passes he may have full blessing. His piety was genuine; the trial proves it. He appeals to the relationship of God with Abraham and to His promises to Solomon, when the latter had built the house. Jehoshaphat understood also the relation in which the enemy stood to Israel, looked at in connection with God's dealings (Ch2 20:10-11). God answers him, and the king encourages the people by acknowledging the voice of the prophets, and by singing the praises of God before the blessing camesinging in faith that His mercy endureth for ever. God abundantly granted his prayer. Israel, whose enemies had slain each other, had only to carry away the spoil; and God gave rest to the king, and his realm was quiet.
Still, if Jehoshaphat no longer united himself with the king of Israel to make war, he joined him in a matter of commerce. But God put a stop to his undertakings.
In spite of some faults the character of Jehoshaphat is a fine one, and refreshes the heart. But soon the sorrowful fruits of his league with Ahab ripen and bring Judah into distress. Jehoram, his son, Ahab's son-in-law, walks in the ways of the kings of Israel. The Edomites revolt, and Libnah, a city of Judah, does the same. The king makes high places, and compels Judah to worship at them. The judgment of God is soon manifested. He whom God has raised up as a witness against the sins of the house of Ahab has foreseen their fruits in Judah; and a writing of Elijah's is brought to the king, [See Note #1] threatening him with the terrible judgments of God. Judah also is attacked by their enemies, who pillage the land, laying waste even the king's house, and slaying all his sons excepting one. This was of Jehovah. It is His government which we see here; for He rules over those who are in covenant with Him, those who are His house.
Note #1
Elijah had been taken up to heaven some time before the writing reached its destination. Being a prophecy, there is nothing which makes any difficulty in believing that this writing, like any other prophecy, was left by Elijah to be used at the suitable time. It was a function which, according to the ways of God, naturally belonged to him as a witness against the iniquity of Ahab.