Talmud zu Bekhorot 2:4
הַמְקַבֵּל צֹאן בַּרְזֶל מִן הַנָּכְרִי, וְלָדוֹת פְּטוּרִין, וּוַלְדֵי וְלָדוֹת חַיָּבִין. הֶעֱמִיד וְלָדוֹת תַּחַת אִמּוֹתֵיהֶם, וַלְדֵי וְלָדוֹת פְטוּרִין, וּוַלדי וַלְדֵי וְלָדוֹת חַיָּבִין. רַבָּן שִׁמְעוֹן בֶּן גַּמְלִיאֵל אוֹמֵר, אֲפִלּוּ עַד עֲשָׂרָה דוֹרוֹת, פְּטוּרִין, שֶׁאַחֲרָיוּתָן לַנָּכְרִי:
Wenn man Schafe zu einem festen Preis von einem Nichtjuden erhält, sind seine Nachkommen von den Pflichten des Erstgeborenen befreit, aber die zweite Generation ist verpflichtet. Wenn man den Nachwuchs als Sicherheit für die Mütter anbietet [sollten sie sterben], ist die zweite Generation befreit, aber die dritte Generation ist verpflichtet. Rabban Shim'on ben Gamliel sagt: Sie sind sogar für zehn Generationen befreit, weil der Nichtjude [verbleibende] Rechte an ihnen hat.
Jerusalem Talmud Yevamot
The Yerushalmi Baba Meṣi‘a 5:7, quoting Tosephta Bekhorot 5:1,14, explains: “What is a mortmain flock? If [the owner] had 100 sheep and said [to the shepherd]: these are stipulated to be worth 100 gold denars, their lambs, their milk, and their shearings are yours, if they die, you are responsible, and for each one you give me a tetradrachma at the end, it is forbidden.” It is forbidden to the shepherd to receive a flock under these conditions from a Jew since most owners will structure the contract so they will make money, which turns the final payment (which accompanies the return of the flock to the owner) into a money-making proposition which looks like interest since the shepherd pays for the use of the flock which he received on credit. It is forbidden to pay interest to Jews. The same kind of contract is permitted with Gentiles. There, we have stated: “If somebody receives [a flock] under mortmain conditions from a Gentile, the young are free, the young’s young are obligated.”47The parallel text is in Baba Meṣi‘a 5:7 (fol. 10b). Rebbi Jeremiah asked: There you say, the young are for the first, and here you say, the young are for the second48In the Mishnah in Bekhorot, lambs are exempt because they belong to the Gentile even though the entire flock is the shepherd’s responsibility whereas the Mishnah here states that mortmain lambs belong to the husband who also carries the same responsibility as the shepherd.! Rebbi Yosa said, there, because the property rights are with the first, the young belong to the first. But here, because the property rights are with the second, the young belong to the second49The contract of the shepherd specifies that the flock must be returned intact at a specified time; the interest of the Gentile is there all the time. In the case of marriage, if the wife predeceases her husband, he inherits from her; his obligation to return the dowry is conditional..