21 And he consulted with the people, and appointed singers to Jehovah, and those that should praise in holy splendour, as they went forth before the armed men, and say, Give thanks to Jehovah; for his loving-kindness [endureth] for ever! 22 And when they began the song of triumph and praise, Jehovah set liers-in-wait against the children of Ammon, Moab, and mount Seir, who had come against Judah, and they were smitten. 23 And the children of Ammon and Moab stood up against the inhabitants of mount Seir, to exterminate and destroy [them]; and when they had made an end of the inhabitants of Seir, they helped to destroy one another. 24 And Judah came on to the mountain-watch in the wilderness, and they looked toward the multitude; and behold, they were dead bodies fallen to the earth, and none had escaped.
Matthew Henry's Commentary on 2 Chronicles 20:21-24
Commentary on 2 Chronicles 20:20-30
(Read 2 Chronicles 20:20-30)
Jehoshaphat exhorted his troops to firm faith in God. Faith inspires a man with true courage; nor will any thing help more to the establishing of the heart in shaking times, than a firm belief of the power, and mercy, and promise of God. In all our trust in the Lord, and our praises of him, let us especially look at his everlasting mercy to sinners through Jesus Christ. Never was an army so destroyed as that of the enemy. Thus God often makes wicked people destroy one another. And never was a victory celebrated with more solemn thanksgivings.