וַיֵּצְאוּ֮ כָּל־בְּנֵ֣י יִשְׂרָאֵל֒ וַתִּקָּהֵ֨ל הָעֵדָ֜ה כְּאִ֣ישׁ אֶחָ֗ד לְמִדָּן֙ וְעַד־בְּאֵ֣ר שֶׁ֔בַע וְאֶ֖רֶץ הַגִּלְעָ֑ד אֶל־יְהוָ֖ה הַמִּצְפָּֽה׃
Then all the children of Israel went out, and the congregation was assembled as one man, from Dan even to Beer-sheba, with the land of Gilead, unto the LORD at Mizpah.
Read midrashic interpretation of Judges 20:1: and classical rabbinic exegesis.