Judges 7:16-18

16Then he divided the three hundred men into three companies, and he put a trumpet into every man’s hand, with empty pitchers, and torches inside the pitchers.

17And he said to them, “Look at me and do likewise; watch, and when I come to the edge of the camp you shall do as I do:

18When I blow the trumpet, I and all who are with me, then you also blow the trumpets on every side of the whole camp, and say, ‘The sword of the Lord and of Gideon!’ ”