Judges 20 38
The agreement was that they would send up a great cloud of smoke to show the town had fallen.
Compare with other 3 random translations
NCV Judges 20:38Now the Israelites had set up a signal with the men in hiding. The men in the surprise attack were to send up a cloud of smoke from the city.
NLT Judges 20:38They had arranged to send up a large cloud of smoke from the town as a signal.
ERV Judges 20:38Now the men of Israel had made a plan with the men who were hiding. The men who were hiding were supposed to send a special signal. They were supposed to make a big cloud of smoke.