Judges 7:16, 19

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.

So Gideon and the hundred men who were with him came to the outskirts of the camp at the beginning of the middle watch, when they had just set the watch. And they blew the trumpets and smashed the jars that were in their hands.