Bava Basra2: 8
מַרְחִיקִין גֹּרֶן קָבוּעַ מִן הָעִיר חֲמִשִּׁים אַמָּה. לֹא יַעֲשֶׂה אָדָם גֹּרֶן קָבוּעַ בְתוֹךְ שֶׁלּוֹ אֶלָּא אִם כֵּן יֶשׁ לוֹ חֲמִשִּׁים אַמָּה לְכָל רוּחַ, וּמַרְחִיק מִנְּטִיעוֹתָיו שֶׁל חֲבֵרוֹ וּמִנִּירוֹ כְּדֵי שֶׁלֹּא יַזִּיק.
One must distance a fixed threshing floor fifty cubits from a town. One may not establish a fixed threshing floor within his own property unless he owns fifty cubits [of land] in every direction, and he must distance [it] from the plantings of his neighbor and from his plowed-over areas so that it should not damage [them].