2 Chronicles 20:2, 3, 12-17, 21, 22, 24

Messengers came and told Jehoshaphat, “A vast army from Edom is marching against you from beyond the Dead Sea. They are already at Hazazon-tamar.” (This was another name for En-gedi.) Jehoshaphat was terrified by this news and begged the Lord for guidance. He also ordered everyone in Judah to begin fasting. 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. His name was Jahaziel son of Zechariah, son of Benaiah, son of Jeiel, son of Mattaniah, a Levite who was a descendant of Asaph. 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. You will find them coming up through the ascent of Ziz at the end of the valley that opens into the wilderness of Jeruel. But you will not even need to fight. Take your positions; then stand still and watch the Lord ’s victory. He is with you, O people of Judah and Jerusalem. Do not be afraid or discouraged. Go out against them tomorrow, for the Lord is with you!” 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.
(2 Chronicles 20:2, 3, 12-17, 21, 22, 24 NLT)