Sukkah 31a
סוכה ל״א א — ד"ה תָּנוּ רַבָּנַן
Sukkah 31a:2
The Mishnah and Gemara discuss a stolen sukkah and establish the halakhic problem of using a sukkah made from another person's materials. The sugya distinguishes between a sukkah that is literally stolen and one built on stolen land, and analyzes the principle that a mitzvah cannot be fulfilled through a transgression.
תָּנוּ רַבָּנַן: סוּכָּה גְּזוּלָה, וְהַמְסַכֵּךְ בִּרְשׁוּת הָרַבִּים — רַבִּי אֱלִיעֶזֶר פּוֹסֵל, וַחֲכָמִים מַכְשִׁירִין. אָמַר רַב נַחְמָן: מַחְלוֹקֶת בְּשֶׁתּוֹקֵף אֶת חֲבֵירוֹ וְהוֹצִיאוֹ מִסּוּכָּתוֹ. וְרַבִּי אֱלִיעֶזֶר לְטַעְמֵיהּ דְּאָמַר: אֵין אָדָם יוֹצֵא יְדֵי חוֹבָתוֹ בְּסוּכָּתוֹ שֶׁל חֲבֵירוֹ. אִי קַרְקַע נִגְזֶלֶת — סוּכָּה גְּזוּלָה הִיא. וְאִי נָמֵי קַרְקַע אֵינָהּ נִגְזֶלֶת — סוּכָּה שְׁאוּלָה הִיא. וְרַבָּנַן לְטַעְמַיְיהוּ, דְּאָמְרִי: אָדָם יוֹצֵא יְדֵי חוֹבָתוֹ בְּסוּכָּתוֹ שֶׁל חֲבֵירוֹ, וְקַרְקַע אֵינָהּ נִגְזֶלֶת, וְסוּכָּה שְׁאוּלָה הִיא.
§ The Sages taught: With regard to a stolen sukka and with regard to one who roofs a sukka in the public domain, which is tantamount to robbing land from the public, Rabbi Eliezer deems these sukkot unfit for use in fulfillment of the mitzva, and the Rabbis deem them fit. Rav Naḥman said: This dispute is limited to a case where one assaults another and forcibly evicts him from his sukka, and takes his place in the sukka. In that case, Rabbi Eliezer deems the sukka unfit. And Rabbi Eliezer conforms to his own reasoning, as he said: A person does not fulfill his obligation with the sukka of another. Therefore, in any event, he does not fulfill his obligation with it. If land can be stolen and acquired by the robber, the sukka from which he evicted the owner is a stolen sukka. And if indeed land cannot be stolen, nevertheless, the robber does not fulfill his obligation according to Rabbi Eliezer, as it is a borrowed sukka. And the Rabbis conform to their reasoning, as they said: A person fulfills his obligation with the sukka of another. And since land cannot be stolen and the sukka is merely a borrowed sukka and not a stolen one, the robber fulfills his obligation, despite the fact that he committed a reprehensible act.

