He arms each man with a trumpet, an empty jar, and a torch. For him to lead his three hundred men to face the vast enemy host and armed only with strange pieces of equipment is rather ridiculous. But Gideon knows that this war cannot be decided by normal weapons of warfare. So he decides to capitalize on what he learned when he eavesdropped on the conversation in the Midianite camp: the enemy was nervous. Gideon planned to exploit this nervousness to the full. He wanted to give Midian the impression that he commands a much larger force than he actually does. He wants to take advantage of the night, and overwhelm them by waking them suddenly with deafening sound and blinding light.
16 And he divided the 300 men into three companies and put trumpets into the hands of all of them and empty jars, with torches inside the jars.