וְיָצְא֥וּ זְקֵנֶ֖יךָ וְשֹׁפְטֶ֑יךָ וּמָדְדוּ֙ אֶל־הֶ֣עָרִ֔ים אֲשֶׁ֖ר סְבִיבֹ֥ת הֶחָלָֽל׃
then thy elders and thy judges shall come forth, and they shall measure unto the cities which are round about him that is slain.
Read midrashic interpretation of Deuteronomy 21:2: and classical rabbinic exegesis.