from 1 Chronicles 20 (NLT)-
Messengers came and told Jehoshaphat, "A vast army from Edom is marching against you from beyond the Dead Sea.... Jehoshaphat was terrifed by this news and begged the Lord for guidance. He also ordered everyone in Judah to begin fasting. So people from all the towns of Judah came to Jerusalem to seek the Lord's help.
Jehoshaphat stood before the community of Judah and Jerusalem in front of the new courtyard at the Temple of the Lord. He prayed, "O Lord, God of our ancestors, you alone are the God who is in heaven. You are ruler of all the kingdoms of the earth. You are powerful and mighty; no one can stand against you! O our God, did you not drive out those who lived in this land when your people Israel arrived? And did you not give this land forever to the descendants of your friend Abraham? Your people settled here and built this Temple to honor your name. They said, 'Whenever we are faced with any calamity such as war, plague, or famine, we can come to stand in your presence before this Temple where your name is honored. We can cry out to you to save us, and you will hear us and rescue us.'
And now see what the armies of Ammon, Moab, and Mount Seir are doing.... For they have come to throw us out of your land.... O our God, won't you stop them? We are powerless against this mighty army that is about to attack us. We do not know what to do, but we are looking to you for help."
As all the men of Judah stood before the Lord with their little ones, wives, and children, the Spirit of the Lord came upon one of the men standing there... He said, "Listen, all you people of Judah and Jerusalem! Listen, King Jehoshaphat! This is what the Lord says: Do not be afraid! Don't be discouraged by this mighty army, for the battle is not yours, but God's. Tomorrow, march out against them.... But you wil not even need to fight. Take your positions; then stand still and watch the Lord's victory.... Go out against them tomorrow, for the Lord is with you!"
Then King Jehoshaphat bowed low with his face to the ground. And all the people of Judah and Jerusalem did the same, worshiping the Lord. Then the Levites... stood to praise the Lord, the God of Israel, with a very loud shout.
Early the next morning the army of Judah went out into the wilderness of Tekoa. On the way, Jehoshaphat stopped and said, "Listen to me, all you people of Judah and Jerusalem! Believe in the Lord your God, and you will be able to stand firm. Believe in his prophets, and you will succeed."
After consulting the people, the king appointed singers to walk ahead of the army, singing to the Lord and praising him for his holy splendor. This is what they sang: "Give thanks to the Lord; his faithful love endures forever!"
At the very moment they began to sing and give praise, the Lord caused the armies of Ammon, Moab, and Mount Seir to start fighting among themselves.... So when the army of Judah arrived at the lookout point in the wilderness, all they saw were dead bodies lying on the ground as far as they could see. Not a single one of the enemy had escaped.
King Jehoshaphat and his men went out to gather the plunder.... There was so much plunder that it took them three days just to collect it all! On the fourth day they gathered in the Valley of Blessing, which got its name that day because the people praised and thanked the Lord there.