The Gemara examines additional dimensions of שומרים and compensation for benefit derived from another's property, raising the broader question of when passive receipt of benefit generates an obligation — a conceptual parallel to the uninvited planter case.
מַתְנִי׳ הַשּׂוֹכֵר פָּרָה מֵחֲבֵירוֹ וְהִשְׁאִילָהּ לְאַחֵר, וּמֵתָה כְּדַרְכָּהּ – יִשָּׁבַע הַשּׂוֹכֵר שֶׁמֵּתָה כְּדַרְכָּהּ, וְהַשּׁוֹאֵל יְשַׁלֵּם לַשּׂוֹכֵר. אָמַר רַבִּי יוֹסֵי: כֵּיצַד הַלָּה עוֹשֶׂה סְחוֹרָה בְּפָרָתוֹ שֶׁל חֲבֵירוֹ? אֶלָּא תַּחְזוֹר פָּרָה לַבְּעָלִים. גְּמָ׳ אֲמַר לֵיהּ רַב אִידִי בַּר אָבִין לְאַבָּיֵי: מִכְּדֵי, שׂוֹכֵר בְּמַאי קָנֵי לְהַאי פָּרָה? בִּשְׁבוּעָה. וְנֵימָא לֵיהּ מַשְׂכִּיר לְשׂוֹכֵר: דַּל אַנְתְּ וְדַל שְׁבוּעֲתָךְ, וַאֲנָא מִשְׁתַּעֵינָא דִּינָא בַּהֲדֵי שׁוֹאֵל. אֲמַר לֵיהּ: מִי סָבְרַתְּ, שׂוֹכֵר בִּשְׁבוּעָה הוּא דְּקָא קָנֵי לַהּ? מִשְּׁעַת מִיתָה הוּא דְּקָנֵי. וּשְׁבוּעָה כְּדֵי לְהָפִיס דַּעְתּוֹ שֶׁל בַּעַל הַבַּיִת.
MISHNA: In the case of one who rents a cow from another, and this renter then lends it to another person, and the cow dies in its typical manner, i.e., of natural causes, in the possession of the borrower, the renter takes an oath to the owner of the cow that the cow died in its typical manner, and the borrower pays the renter for the cow that he borrowed. A renter is exempt in a case of damage due to circumstances beyond his control, including death, but a borrower is liable to compensate the owner even for damage due to circumstances beyond his control. Rabbi Yosei said: How does the other party, i.e., the renter, do business with and profit from another’s cow? Rather, the value of the cow should be returned to the owner. The renter need not take an oath, but the borrower must compensate the owner of the cow. GEMARA: Rav Idi bar Avin said to Abaye: After all, with regard to the renter, with what does he acquire this cow to the extent that one who borrows the cow from him is liable to compensate him if it dies? He acquires it with an oath that he took to the owner of the cow that the cow died of natural causes. The Gemara asks: But since the acquisition is effected by the renter’s oath, let the one who rented his animal for hire say to the renter: Remove yourself and remove your oath. I do not want to deal with you at all in this case, and I will litigate with the borrower to recover my cow. Abaye said to Rav Idi bar Avin: Do you hold that it is with an oath that the renter acquires the cow? That is not so, as from the moment of the cow’s death, the renter acquires the cow. From the moment the cow dies in the possession of the borrower, the renter has the right to receive another cow in exchange. And this oath that the renter takes to the owner of the cow is not required by the halakha. Rather, he takes the oath to alleviate the concerns of the owner, so that the owner will not suspect him of negligence. Consequently, the owner of the cow cannot litigate with the borrower, and even if he waives his right to demand an oath from the renter, he is unable to receive a cow from the borrower.