Judges 21:4-6 New International Version - UK (NIVUK)
4 Early the next day the people built an altar and presented burnt offerings and fellowship offerings.
5 Then the Israelites asked, ‘Who from all the tribes of Israel has failed to assemble before the Lord?’ For they had taken a solemn oath that anyone who failed to assemble before the Lord at Mizpah was to be put to death.
6 Now the Israelites grieved for the tribe of Benjamin, their fellow Israelites. ‘Today one tribe is cut off from Israel,’ they said.