Bekhorot 2B

מאי לאו אעובר? לא, אבהמה.

What, is it not referring to the fetus when the baraita states that he is not permitted to sell it? The Talmud responds: No, it is referring to the animal itself that he may not sell to the non-Jew, and that is why he is penalized.

והא ״דמיו״ קתני! תני ״דמיה״. והא ״נותן כל דמיו לכהן״ קתני, ואי בהמה ⁠— כהן מאי עבידתיה? הכא במאי עסקינן ⁠— כגון דיהיב ליה בהמה מעברתא לפטומה, דמיגו דקנסינן ליה אבהמה, קנסינן ליה אעובר.

The Talmud asks: But doesn’t the baraita teach: The rabbis penalize him up to 10 times its value [damav], in masculine form, indicating that it is referring to the fetus and not the mother? The Talmud responds: Teach the following wording in the baraita: The rabbis penalize him up to 10 times its value [dameha], in feminine form. The Talmud asks: But doesn’t it teach: He gives all of its value to the priest? And if it is referring to the animal and not the firstborn, what is the relevance of the priest? The Talmud answers: Here we are dealing with a case where the Jew gave the non-Jew a pregnant animal to fatten it in order to divide the profits as well as the offspring. Since we penalize him for selling the animal in a prohibited manner, we penalize him with regard to the fetus as well.

אמר רב אשי: תא שמע, רבי יהודה מתיר בשבורה, מפני שאינה יכולה להתרפאות. הא יכולה להתרפאות ⁠— אסר, והא עובר נמי כיכול להתרפאות דמי. שמע מינה.

Rav Ashi says: Come and hear a resolution from a baraita: R' Yehuda deems the sale to a non-Jew of a damaged animal permitted, because it is incapable of being cured. This statement indicates that if it is capable of being cured, R' Yehuda deems its sale prohibited. And a fetus is also similar to one who is able to be cured, as it ultimately will be capable of working. Learn from it that R' Yehuda deems the sale of a fetus to a non-Jew prohibited.