וּמִגְרְשֵׁי֙ הֶֽעָרִ֔ים אֲשֶׁ֥ר תִּתְּנ֖וּ לַלְוִיִּ֑ם מִקִּ֤יר הָעִיר֙ וָח֔וּצָה אֶ֥לֶף אַמָּ֖ה סָבִֽיב׃
And the open land about the cities, which ye shall give unto the Levites, shall be from the wall of the city and outward a thousand cubits round about.
Read halakhic rulings (Jewish law) on Numbers 35:4: and classical halakhic sources.