15הַלּוֹקֵחַ עֻבַּר חֲמוֹרוֹ שֶׁל עַכּוּ"ם אוֹ הַמּוֹכֵר עֻבַּר חֲמוֹרוֹ לְעַכּוּ"ם אַף עַל פִּי שֶׁאֵינוֹ רַשַּׁאי הֲרֵי זֶה פָּטוּר מִן הַבְּכוֹרָה. וְאֵין קוֹנְסִין אוֹתוֹ עַל דָּבָר זֶה. הָיָה הָעַכּוּ"ם שֻׁתָּף בָּאֵם אוֹ בַּבְּכוֹר אֲפִלּוּ לֹא הָיָה לוֹ אֶלָּא אֶחָד מֵאֶלֶף בּוֹ הֲרֵי זֶה פָּטוּר. הָיָה לוֹ בּוֹ אוֹ בְּאִמּוֹ אֵיבָר אֶחָד כְּגוֹן יָדוֹ אוֹ רַגְלוֹ אֲפִלּוּ אָזְנוֹ כָּל שֶׁאִלּוּ יֵחָתֵךְ יִהְיֶה בַּעַל מוּם הֲרֵי זֶה פָּטוּר מִן הַבְּכוֹרָה. וְאִם כְּשֶׁיֵּחָתֵךְ חֵלֶק הָעַכּוּ"ם לֹא יִהְיֶה בַּעַל מוּם לַמִּזְבֵּחַ הֲרֵי זֶה חַיָּב. וְכֵן הַמְקַבֵּל חֲמוֹר מִן הָעַכּוּ"ם לִהְיוֹת מְטַפֵּל בָּהּ וְהַוָּלָד בֵּינֵיהֶם אוֹ עַכּוּ"ם שֶׁקִּבֵּל מִיִּשְׂרָאֵל הַכּל פָּטוּר מִן הַבְּכוֹרָה שֶׁנֶּאֱמַר (שמות יג ב) "פֶּטֶר רֶחֶם בִּבְנֵי יִשְׂרָאֵל בָּאָדָם וּבַבְּהֵמָה" עַד שֶׁיִּהְיֶה הַכּל בְּיִשְׂרָאֵל:
When a person purchases the fetus of a donkey belonging to a gentile or sells the fetus of his donkey to a gentile - although he is not allowed to do so - he is exempt from [redeeming] the firstborn. We do not penalize him for such an act. If the gentile was a partner in the mother or the firstborn - even if he only owned a thousandth share - the animal is exempt. Should [the gentile own] only one limb or organ of the fetus or the mother - e.g., its forefoot or its hindfoot, even its ear, any limb or organ that if cut off would cause the animal to be disqualified as blemished - it is exempt from [the obligations of] a firstborn. If, however, the portion belonging to the gentile would be cut off, the animal would not be considered as blemished for the altar, he is obligated. Similarly, one who receives a donkey from a gentile to care for on the condition that they divide the offspring or a gentile received [a donkey] from a Jew on that condition, they are exempt from [the obligations of] the firstborn, as [indicated by Exodus 13:2]: "The first issue of the womb within the children of Israel, in humans and in animals." [Implied is that] it must entirely belong to an Israelite.