2 Chronicles 20:13-23

Meanwhile all Judah stood before the Lord, with their little ones, their wives, and their children. Then the spirit of the Lord came upon Jahaziel son of Zechariah, son of Benaiah, son of Jeiel, son of Mattaniah, a Levite of the sons of Asaph, in the middle of the assembly. He said, ‘Listen, all Judah and inhabitants of Jerusalem, and King Jehoshaphat: Thus says the Lord to you: “Do not fear or be dismayed at this great multitude; for the battle is not yours but God’s. Tomorrow go down against them; they will come up by the ascent of Ziz; you will find them at the end of the valley, before the wilderness of Jeruel. This battle is not for you to fight; take your position, stand still, and see the victory of the Lord on your behalf, O Judah and Jerusalem.” Do not fear or be dismayed; tomorrow go out against them, and the Lord will be with you.’

Then Jehoshaphat bowed down with his face to the ground, and all Judah and the inhabitants of Jerusalem fell down before the Lord, worshipping the Lord. And the Levites, of the Kohathites and the Korahites, stood up to praise the Lord, the God of Israel, with a very loud voice.

They rose early in the morning and went out into the wilderness of Tekoa; and as they went out, Jehoshaphat stood and said, ‘Listen to me, O Judah and inhabitants of Jerusalem! Believe in the Lord your God and you will be established; believe his prophets.’ When he had taken counsel with the people, he appointed those who were to sing to the Lord and praise him in holy splendour, as they went before the army, saying,
‘Give thanks to the Lord,
for his steadfast love endures for ever.’
As they began to sing and praise, the Lord set an ambush against the Ammonites, Moab, and Mount Seir, who had come against Judah, so that they were routed. For the Ammonites and Moab attacked the inhabitants of Mount Seir, destroying them utterly; and when they had made an end of the inhabitants of Seir, they all helped to destroy one another.