“Then they said. ‘Is there anyone from the tribes of Israel who did not come up to Yahweh to Mizpah?’ It turned out that no one from Jabesh-gilead had come to the camp, to the assembly. For when the roll was called among the people, not one of the inhabitants of Jabesh-gilead was there. So the congregation sent twelve thousand soldiers there and commanded them. ‘Go! Put the inhabitants of Jabesh-gilead to the sword, including the women and the little ones. This is what you shall do. Every male and every woman who has laid with a male you shall devote to destruction.’ They found among the inhabitants of Jabesh-gilead four hundred young virgins who had never slept with a man. They brought them to the camp at Shiloh, which is in the land of Canaan.”
They tried to figure out who did not make the oath of not letting our young women marry the Benjaminites. One place that did not send anybody to the meeting at Mizpah was Jabesh-gilead. This town was on the east side of the Jordan, obviously in Gilead, in the territory of Manasseh. They decide to kill all the people in this town except for the virgins, which was around 400, so that they could become the wives of the Benjaminites.
“Then the whole congregation sent word to the Benjaminites who were at the rock of Rimmon. They proclaimed peace to them. Benjamin returned at that time. They gave them the women whom they had saved alive from the women of Jabesh-gilead. But they did not suffice for them.”
Now there is a peace treaty with the remaining 600 Benjaminites at Rimmon. They will get the 400 virgins of Jabesh-gilead. However, since there were 600 men that meant that they still needed another 200 women.