2 Chronicles 20:23
For the children of Ammon and Moab stood up against the inhabitants of mount Seir, utterly to slay and destroy them: and when they had made an end of the inhabitants of Seir, every one helped to destroy another. For the children of Ammon and Moab stood up against the inhabitants of mount Seir, utterly to slay and destroy them: and when they had made an end of the inhabitants of Seir, every one helped to destroy another.
Judah went out trusting God and His prophet, praising the beauty of His holiness in advance before any battle was fought. In response the Lord set ambushes against the combined invaders from Ammon, Moab, and Mount Seir, turning those invading forces against each other.
Ammon and Moab rose up against the inhabitants of Mount Seir and utterly slew and destroyed them. When they had made an end of Seir, every man then helped to destroy the other, so the Ammonites and Moabites destroyed one another. By this turning of the enemy armies against one another they brought about their own complete mutual destruction and Judah's victory.
That mutual slaughter left the whole attacking force as dead bodies fallen to the earth, with none escaping. Judah therefore did not have to fight the invaders or defeat them by its own army, but had only to stand still and see the salvation of the Lord. This Judah saw when it came to the watchtower and looked out over the multitude and beheld the dead.
Then Judah returned to Jerusalem with joy and with music to the house of the Lord, carrying the enemies' spoil. They sang praise for the victory God had promised and given. Because the Lord had fought against Israel's enemies, the fear of the Lord fell upon all the surrounding kingdoms. So Jehoshaphat's realm was quiet, for his God gave him rest round about.