The Israelites asked, “Who among all the tribes of Israel did not come to the assembly before the LORD?” For they had taken a solemn oath that anyone who failed to come up before the LORD at Mizpah would surely be put to death.
Jewish Publication Society of America Version (JPS1917) - Judges 21:5 >And the children of Israel said: 'Who is there among all the tribes of Israel that came not up in the assembly unto the LORD?' For they had made a great oath concerning him that came not up unto the LORD to Mizpah, saying: 'He shall surely be put to death.'