20 So they rose early in the morning and went out into the Wilderness of Tekoa; and as they went out, Jehoshaphat stood and said, "Hear me, O Judah and you inhabitants of Jerusalem: Believe in the Lord your God, and you shall be established; believe His prophets, and you shall prosper." 21 And when he had consulted with the people, he appointed those who should sing to the Lord, and who should praise the beauty of holiness, as they went out before the army and were saying: "Praise the Lord, For His mercy endures forever." 22 Now when they began to sing and to praise, the Lord set ambushes against the people of Ammon, Moab, and Mount Seir, who had come against Judah; and they were defeated.
Matthew Henry's Commentary on 2 Chronicles 20:20-22
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.