What does it mean that those who came out of the cities were destroying them in their midst?
Judges 20:42 (ESV)
42Therefore they turned their backs before the men of Israel in the direction of the wilderness, but the battle overtook them. And those who came out of the cities were destroying them in their midst.
The final clause of the verse is somewhat enigmatic. It likely refers to those who had gone to raid and destroy Gibeah. They joined in on the chase with Israel, destroying the fleeing Benjamites.
42 Therefore they turned their backs before the men of Israel in the direction of the wilderness, but the battle overtook them. And those who came out of the cities were destroying them in their midst.