2 Chronicles - Chapter 20

The armies of the Moabites, Ammonites, and some of the Meunites declared war on Jehoshaphat.

Following God's instructions Jehoshaphat's people march against these armies, singing praises to God.  But they do not need to fight, as God himself fights for them.  When they arrived at the enemy army all they saw were dead bodies.  Every one of the enemy soldiers was already dead/

In the book of Joel we read about the time of restoration, to be achieved through Jesus' coming.  God says that this will be a time like the time of Jehoshaphat with God judging the people :

“At the time of those events,” says the Lord,
   “when I restore the prosperity of Judah and Jerusalem,
I will gather the armies of the world
   into the valley of Jehoshaphat.
There I will judge them
   for harming my people, my special possession,
for scattering my people among the nations,
   and for dividing up my land."