וְאִ֣ישׁ יִשְׂרָאֵ֔ל נִשְׁבַּ֥ע בַּמִּצְפָּ֖ה לֵאמֹ֑ר אִ֣ישׁ מִמֶּ֔נּוּ לֹא־יִתֵּ֥ן בִּתּ֛וֹ לְבִנְיָמִ֖ן לְאִשָּֽׁה׃
Now the men of Israel had sworn in Mizpah, saying: ‘There shall not any of us give his daughter unto Benjamin to wife.’
Read halakhic rulings (Jewish law) on Judges 21:1: and classical halakhic sources.