22 And when they began to sing and praise, the Lord set an ambush against the men of Ammon, Moab, and Mount Seir, who had come against Judah, so that they were routed. 23 For the men of Ammon and Moab rose against the inhabitants of Mount Seir, devoting them to destruction, and when they had made an end of the inhabitants of Seir, they all helped to destroy one another. 24 When Judah came to the watchtower of the wilderness, they looked toward the horde, and behold, there[1] were dead bodies lying on the ground; none had escaped. 25 When Jehoshaphat and his people came to take their spoil, they found among them, in great numbers, goods, clothing, and precious things, which they took for themselves until they could carry no more. They were three days in taking the spoil, it was so much. 26 On the fourth day they assembled in the Valley of Beracah,[2] for there they blessed the Lord. Therefore the name of that place has been called the Valley of Beracah to this day. 27 Then they returned, every man of Judah and Jerusalem, and Jehoshaphat at their head, returning to Jerusalem with joy, for the Lord had made them rejoice over their enemies. 28 They came to Jerusalem with harps and lyres and trumpets, to the house of the Lord. 29 And the fear of God came on all the kingdoms of the countries when they heard that the Lord had fought against the enemies of Israel. 30 So the realm of Jehoshaphat was quiet, for his God gave him rest all around.

Matthew Henry's Commentary on 2 Chronicles 20:22-30

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.