So the people took food in their hand, and their trumpets; and he sent all the men of Israel every man to his tent, but retained the three hundred men: and the camp of Midian was beneath him in the valley.
The text does not enable us to understand God’s motive certainly. Simple obedience is what He required. Before God told Gideon to let the larger group of soldiers go home, He gave him a promise that He would deliver Israel with the 300 remaining warriors. This promise undoubtedly encouraged Gideon’s faith.