HIS ARM OF AMBUSHMENT

Three nations rose against Judah under Jehoshaphat. The connivance of these nations was a big threat to the Jews, for they were a great multitude such that Jehoshaphat could not contain because there were indeed a great multitude. The nations, Ammon, Moab and Mount Seir agreed to disgrace the people of Judah by humiliating then in a diplomatic battle.
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And Jehoshaphat feared and set himself to seek the Lord, and proclaimed a fast throughout all Judah.

So, Judah gathered together and asked help from God, from all the cities if Judah people came to seek the help of the Lord. Jehoshaphat said:
"O Lord of our fathers, are you not God in heaven, and do you not rule over all the kingdoms of the nations, and in your hands is there not power and might, so that no one is able to withstand you?"
After that he had mentioned all these word of prayers to God, ten , of God came upon Jahaziel who delivered a message from God to Jehoshaphat and the people of Judah saying:
"Listen, all you of Judah and you inhabitants of Jerusalem and you King Jehoshaphat! Thus says the Lord to you:'Do not be afraid nor dismayed, for the battle is not yours but God's"
The prophet told the people to position themselves with instruments if songs in the Ascent of Ziz.
One may begin to imagine, how could God ask people to sing instead of go out and face the enemy headlong. Truth is that the ways of God is not the ways of man.
The people rose early in the morning and went into the wilderness of Tekoa and they began to sing to God. Now the Lord Himself set ambushes against the people of Ammon, Moab and Mount Seir. For the people of Ammon and Moab stood up against the inhabitants of Mount Seir to utterly kill and destroy them. And when they had made an end of the inhabitants of Seir, they helped to destroy one another.
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The people of Judah and Jehoshaphat on arrival to the battlefield only saw heaps of corpse and began to take away the spoil which they did for three days and on the fourth day they got to the valley of Berachah where they dwell until this day.