כָּל הַקַּרְקָעוֹת הַיְדוּעוֹת לבַעְלֵיהֶן אַף עַל פִּי שֶׁהֵן עַתָּה תַּחַת יַד אֲחֵרִים הֲרֵי הֵן בְּחֶזְקַת בַּעְלֵיהֶן. כֵּיצַד. רְאוּבֵן שֶׁהָיָה מִשְׁתַּמֵּשׁ בֶּחָצֵר כְּדֶרֶךְ שֶׁהָעָם מִשְׁתַּמְּשִׁין בְּחַצְרוֹתֵיהֶן. דָּר בָּהּ וּמַשְׂכִּירָהּ לַאֲחֵרִים וּבוֹנֶה וְסוֹתֵר. וְאַחַר זְמַן בָּא שִׁמְעוֹן וְטָעַן עָלָיו וְאָמַר לוֹ חָצֵר זוֹ שֶׁתַּחַת יָדְךָ שֶׁלִּי הִיא וּשְׂכוּרָה הִיא בְּיָדְךָ אוֹ שְׁאוּלָה. וֶהֱשִׁיבוֹ רְאוּבֵן שֶׁלְּךָ הָיְתָה וְאַתָּה מְכַרְתָּהּ לִי אוֹ נְתַתָּהּ לִי בְּמַתָּנָה. אִם אֵין עֵדִים לְשִׁמְעוֹן שֶׁהָיְתָה יְדוּעָה לוֹ נִשְׁבָּע רְאוּבֵן הֶסֵּת וְיַעֲמֹד בִּמְקוֹמוֹ. אֲבָל אִם הֵבִיא שִׁמְעוֹן עֵדִים שֶׁחָצֵר זוֹ שֶׁלּוֹ הָיְתָה הֲרֵי הִיא בְּחֶזְקַת שִׁמְעוֹן וְאוֹמְרִין לִרְאוּבֵן הָבֵא רְאָיָה שֶׁמְּכָרָהּ לְךָ אוֹ נְתָנָהּ לְךָ. וְאִם לֹא הֵבִיא רְאָיָה מְסַלְּקִין אוֹתוֹ מִמֶּנָּה וּמַחֲזִיקִין אוֹתָהּ לְשִׁמְעוֹן אַף עַל פִּי שֶׁאֵין רְאוּבֵן מוֹדֶה לְשִׁמְעוֹן שֶׁהִיא הָיְתָה שֶׁלּוֹ שֶׁהֲרֵי יֵשׁ עֵדִים לְשִׁמְעוֹן:
Whenever landed property is known to have belonged to a person, we presume that he is the owner even though the property is now in the possession of another person. What is implied? Reuven was using a courtyard as a person would commonly use his own property, living in it, renting it to others, building and tearing down structures. After a while, Shimon came and lodged a claim against him, saying: "The courtyard that is in your possession belongs to me. I rented it to you," or "... I lent it to you." Reuven replied: "It was yours, but you sold it to me," or "You gave it to me as a present." If Shimon does not bring witnesses who testify that it was known to belong to him, Reuven is required to take a sh'vu'at hesset, and he is allowed to retain possession of the courtyard. If, however, Shimon brings witnesses who testify that this field belonged to him, our presumption is that Shimon is the owner. We tell Reuven: "Bring proof that he sold it to you or gave it to you." If he does not bring proof, we force him to leave and establish Shimon as the owner. This law applies even when Reuven does not admit that the field ever belonged to Shimon, because there are witnesses who support Shimon's claim.
