Reference for Maaser Sheni 5:2
כֶּרֶם רְבָעִי הָיָה עוֹלֶה לִירוּשָׁלַיִם מַהֲלַךְ יוֹם אֶחָד לְכָל צָד. וְאֵיזוֹ הִיא תְחוּמָהּ, אֵילַת מִן הַדָּרוֹם וְעַקְרַבַּת מִן הַצָּפוֹן, לוֹד מִן הַמַּעֲרָב וְהַיַּרְדֵּן מִן הַמִּזְרָח. וּמִשֶּׁרַבּוּ הַפֵּרוֹת, הִתְקִינוּ שֶׁיְּהֵא נִפְדֶּה סָמוּךְ לַחוֹמָה. וּתְנַאי הָיָה הַדָּבָר, שֶׁאֵימָתַי שֶׁיִּרְצוּ, יַחֲזֹר הַדָּבָר לִכְמוֹת שֶׁהָיָה. רַבִּי יוֹסֵי אוֹמֵר, מִשֶּׁחָרַב בֵּית הַמִּקְדָּשׁ, הָיָה הַתְּנַאי הַזֶּה. וּתְנַאי הָיָה, אֵימָתַי שֶׁיִּבָּנֶה בֵּית הַמִּקְדָּשׁ, יַחֲזֹר הַדָּבָר לִכְמוֹת שֶׁהָיָה:
<i>Kerem Revai</i> was brought to Jerusalem from a radius of a day-long journey. And what is its boundary? From Eilat in the south and Akrabat in the north. From Lod in the west and the Jordan river in the east. And when the produce increased, they decreed that it could be redeemed even up to the wall. And the matter was conditional—that whenever they wanted, the matter would revert to how it was originally. Rabbi Yosi says: This condition was made when the Temple was destroyed, and the condition was that whenever the Temple would be rebuilt, the matter would revert to how it was originally.