Then all the tribes, except Benjamin, which was having its own colloquy sent out delegates to Mizpah to hear the story first hand and decide what to do. Such a breach of the rules of hospitality could not stand. God once destroyed two cities for such things. If they let it slide, God might get mad and go on a smiting spree.
So the tribes decided to draft 10% of their fighting men to go punish Gibeah. They sent messages to all the clans of Benjamin declaring that punishment must come forthwith, urging Benjamin to hand over such malefactors to the justice of the Lord.
Benjamin told them to go suck it, and sent their fighting men to defend Gibeah.
The Benjaminites mustered 26,700 men, including Gibeah’s squadron of crack-shot, left-handed slingers, to fight against the 400,000 men who represented the rest of Israel.
God told the leaders to attack Gibeah, but the Benjaminites routed them, killing over 20,000 men. Despite the losses, the Hebrews didn’t falter when God told them to march out the next day. Again, Benjamin won and killed thousands upon thousands of men. The Hebrews prayed again, and again God told them to go up. But this time, the Hebrews set up an ambush. They completely destroyed the Benjaminites, killing over 90% of them.
Then the Hebrews forces pillaged and burned Gibeah and pretty much every Benjaminite city they came across. All but a handful of fighting men died.