民数記 35:2

ומגרש AND OPEN LAND — an area consisting of an open space round about the city outside it, serving to beautify the city. It was not permitted to build houses there nor to plant vineyards nor to sow a plantation (cf. Arakhin 33b).

צַו֮ אֶת־בְּנֵ֣י יִשְׂרָאֵל֒ וְנָתְנ֣וּ לַלְוִיִּ֗ם מִֽנַּחֲלַ֛ת אֲחֻזָּתָ֖ם עָרִ֣ים לָשָׁ֑בֶת וּמִגְרָ֗שׁ לֶֽעָרִים֙ סְבִיבֹ֣תֵיהֶ֔ם תִּתְּנ֖וּ לַלְוִיִּֽם׃

Command the children of Yisra᾽el, that they give to the Levites of the inheritance of their possession cities to dwell in; and you shall give also to the Levites an open space for the cities round about them.