Mishnayos Kilayim Perek 6 Mishnah 6

Gaps in an aris must be eight cubits and somewhat more [in order to be able to sow seeds in the gaps]. [In the case of] all measurements that the sages said in connection with a vineyard, there is no ‘and somewhat more’, except in the case of gaps in an aris. The following count as gaps in an aris: if an aris was razed in its middle and five vines remained on one side and five vines on the other side. Then if the gap is [only] eight cubits, one may not bring seed there. [But if the gap is] eight cubits and somewhat more, they give [the vines] space to work them, and he may sow the rest.

פִּסְקֵי עָרִיס, שְׁמֹנֶה אַמּוֹת וָעוֹד. וְכָל מִדּוֹת שֶׁאָמְרוּ חֲכָמִים בַּכֶּרֶם, אֵין בָּהֶם וָעוֹד, חוּץ מִפִּסְקֵי עָרִיס. אֵלוּ הֵן פִּסְקֵי עָרִיס, עָרִיס שֶׁחָרַב מֵאֶמְצָעוֹ וְנִשְׁתַּיְּרוּ בוֹ חָמֵשׁ גְּפָנִים מִכָּאן וְחָמֵשׁ גְּפָנִים מִכָּאן. אִם יֵשׁ שָׁם שְׁמֹנֶה אַמּוֹת, לֹא יָבִיא זֶרַע לְשָׁם. שְׁמֹנֶה אַמּוֹת וָעוֹד, נוֹתְנִין לוֹ כְדֵי עֲבוֹדָתוֹ, וְזוֹרֵעַ אֶת הַמּוֹתָר: