QUESTION: The Mishnah teaches that when a Jew buys an unborn fetus of the donkey of a Nochri, or when he sells an unborn fetus to a Nochri, the foal does not have the Kedushah of a Bechor when it is born.
The Mishnah implies that it is possible to sell an unborn fetus without selling the mother animal itself. How, though, can one sell the unborn offspring of his animal? Since it has not yet been born, it is considered a "Davar she'Lo Ba l'Olam" -- an object that does not yet exist, on which a Kinyan cannot take effect (Bava Basra 79b)!
Indeed, the TUR and SHULCHAN ARUCH (CM 209:4) rule that when one says to a buyer with regard to his animal's fetus, "What will be born to my animal will belong to you," the sale is not valid. A fetus is considered a Davar she'Lo Ba l'Olam until it is born. The Rishonim (see HAGAHOS ASHIRI to Bava Basra 9:5; see also Shulchan Aruch YD 320:6) point out that this applies to an unborn Bechor as well; a fetus cannot be sold to a Nochri so that the Bechor that will be born will belong to the Nochri. Why, then, does the Mishnah state that such a transaction takes effect?
Although Rebbi Meir maintains that the sale of a Davar she'Lo Ba l'Olam does take effect, the Halachah follows the view of the Chachamim who maintain that a person does not have the right to sell what is not yet in his possession. Does the Mishnah here follow the view of Rebbi Meir, which is not the Halachah?
(a) TOSFOS (3b, end of DH d'Ka) quotes RABEINU TAM who explains that the sale of an unborn fetus is valid when the owner of the animal stipulates that he is selling "the animal for the purpose of keeping its foal when it will be born," as opposed to selling the fetus itself. That is, the mother animal is being sold with regard to the rights to the offspring that it will produce; the unborn fetus itself is not being sold. The buyer is purchasing the animal for a specific use: to have rights to the offspring that the animal produces (see Bava Basra 132b and 147b). Since the animal itself exists, the sale does not involve a Davar she'Lo Ba l'Olam.
However, the BRISKER RAV (Bechoros 3b) proves from the Gemara here that the sale of the fetus takes effect even when one does not use the formula suggested by Rabeinu Tam. The Gemara discusses the question of whether one is permitted in the first place to sell the fetus of an animal to a Nochri, and then, in a separate discussion (2b), it asks whether or not one is permitted to sell to a Nochri "an animal for the sake of keeping its fetus"!
(b) The NIMUKEI YOSEF and ME'IRI in Bava Basra (80a) point out that although the seller may back out of the sale of a Davar she'Lo Ba l'Olam at any time, if he does not back out of the sale the buyer is entitled to keep what he purchased. Accordingly, the Mishnah might be discussing a case in which the seller does not back out of the sale.
(c) The NESIVOS HA'MISHPAT (CM 209:2) explains that a fetus is considered to be in existence as a piece of flesh. Only with regard to being a living animal is it not considered to exist until it is born. One who stipulates that the unborn animal will be sold from the moment it is born is attempting to sell a Davar she'Lo Ba l'Olam and the sale is not valid. In contrast, when one sells a fetus in its present state, as a piece of flesh, the sale takes effect just as it would take effect for any other internal organ of a live animal. When Tosfos and the Hagahos Ashiri write that a fetus cannot be sold, they mean that it cannot be sold as a baby animal; they agree that it can be sold as a piece of flesh.
(d) The NETZIV (in Meromei Sadeh to Bava Basra 80a) suggests, based on numerous inferences, that a rabbinic institution exists whereby any type of transaction that people become accustomed to conducting on a regular basis gains validity, even if that transaction involves the transfer of a Davar she'Lo Ba l'Olam.
HAGA'ON RAV YISRAEL ZEV GUSTMAN zt'l (in Kuntresei Shi'urim, Bava Metzia 13:2) cites the HAGAHOS MORDECHAI (end of Shabbos #472, and also cited in brief by the KETZOS HA'CHOSHEN 201), who writes that a very similar point was debated among the Rishonim. The MAHARAM said that when people become accustomed to a type of transaction in which an object that is a Davar she'Lo Ba l'Olam is traded, the trade becomes valid through the Kinyan of "Situmta," which gives Halachic validity to any commonplace practice used to finalize a pecuniary agreement (see Bava Metzia 74a). RABEINU YECHIEL argues and says that even the principle of "Situmta" cannot make the transfer of a Davar she'Lo Ba l'Olam a valid transaction. (See Insights to Bava Basra 80:1.)
QUESTION: The Mishnah says that when a Jew sells an unborn fetus of a donkey to a Nochri, "even though he is not permitted to do so," the foal is exempt from the law of Bechor when it is born. RASHI (DH Af Al Pi) cites the Gemara in Avodah Zarah (14b) that teaches that one may not sell a Behemah Gasah, a large, domesticated animal, to a Nochri, because of the concern that the Nochri will make it work on Shabbos. Rashi later (DH Patur) explains that the reason why the foal does not have the Kedushah of a Bechor is because of the Nochri's ownership of it.
It is clear from the Mishnah that even though one is forbidden to sell such an animal to a Nochri, the sale nevertheless takes effect. However, in the Gemara in Kesuvos (81b), Rav Yosef rules that any sale that the Rabanan prohibited does not take effect even b'Di'eved. The GILYON MAHARSHA there explains that this is based on the principle that "Iy Avid Lo Mehani" -- if one performs an act that the Torah prohibits, the act does not take effect (Temurah 4b), which, according to some, applies even to an act prohibited by the Rabanan.
Why, then, is the sale of a donkey to a Nochri valid? Since the Rabanan said that one may not sell a donkey to a Nochri, the sale should be invalid and the firstborn foal should have the Kedushah of a Bechor.
(a) The SHAI LA'MORA answers that even though there is a prohibition against selling an animal to a Nochri, there is a different consideration with regard to the laws of Bechor. The Mishnah later (16a) states that when a Jew receives a flock of animals from a Nochri for a term of ten years with the condition that he return a fixed sum of the value of the flock and he and the Nochri will share all of the offspring produced, the offspring are exempt from the laws of Bechor. The Gemara (16b) explains that this is because the Nochri has the rights to appropriate his animals if the Jew does not pay the Nochri what he is entitled to receive, and thus "Yad Nochri ba'Emtza" -- the Nochri owns part of the offspring and thus exempts them from the laws of Bechor (as derived from Bamidbar 3:13; see also Pesachim 6a).
Similarly, in the case of the Mishnah here, even if the sale of the animal to the Nochri is not valid, since the Nochri paid money for the fetus he will keep the animal if the Jew does not return his money to him. Accordingly, in this case as well the Nochri is considered to own the offspring because "Yad Nochri ba'Emtza" and thus it is exempt from the laws of Bechor.
(b) REBBI AKIVA EIGER (in Chidushim to Kesuvos 81b) writes that the principle of "Iy Avid Lo Mehani" applies only to Isurim d'Oraisa, and not to Isurim d'Rabanan; if a person does an act which is an Isur d'Rabanan, the act still takes effect. This is implied by the wording of the principle itself, "Kol Milsa d'Amur Rachmana Lo Ta'avid, Iy Avid Lo Mehani," implying that if the Rabanan prohibited the act, it nevertheless takes effect if one transgresses their word and performs the act.
Rebbi Akiva Eiger writes that even though the Gemara in Kesuvos says that a sale that the Rabanan prohibited does not take effect even b'Di'eved, this does not apply to all prohibited sales. The SHULCHAN ARUCH (CM 195:11 and 235:28) rules that although one is prohibited to conduct a transaction on Shabbos, a transaction that was conducted on Shabbos is binding. The case in Kesuvos is different. There, the Gemara is discussing the brother-in-law of a Yevamah, whom the Rabanan prohibited from selling his brother's estate. In order to prevent the deceased brother's estate from suffering a loss, the Rabanan prohibited selling it, and they decreed that any sale is not binding even b'Di'eved. We cannot derive from that specific case that in all other cases of a prohibited sale (such as making a sale on Shabbos, or selling an animal to a Nochri) the sale is also not binding.
Therefore, just as a transaction performed on Shabbos is valid b'Di'eved, when one sells a donkey to a Nochri the sale is valid b'Di'eved. (See also Insights to Chulin 8:2 and Bava Kama 70:2.) (D. BLOOM)


OPINIONS: The Gemara quotes Avuha d'Shmuel (the father of Shmuel) who ruled that a Jew may not enter a partnership with a Nochri, because perhaps a dispute will arise and the Nochri will make an oath in the name of his idol. A Jew is not allowed to cause anyone to swear by the name of an idol.
Does this imply that if a Jew has a dispute with a Nochri, for whatever reason (even if they are not partners), and the Nochri wants to swear by his idol, the Jew should pay the disputed sum in order to avoid causing the Nochri to swear?
(a) TOSFOS (DH Shema) and the ROSH (1:1) quote the RASHBAM who rules that the Jew should pay the disputed sum in order to avoid causing the Nochri to swear in the name of his idol. (See also TOSFOS to Sanhedrin 63b, DH Asur, and ROSH there, 7:3).
(b) Tosfos here and in Sanhedrin cites RABEINU TAM who disagrees and permits a Jew to have a Nochri swear to him in court. He gives two reasons for why this is permitted. His first reason is that causing a Nochri to swear is permitted in order to prevent a monetary loss. Avuha d'Shmuel's ruling only prohibits forming a partnership with a Nochri, because at that point the Jew is not in imminent danger of losing money.
His second reason is that nowadays Nochrim do not swear with the name of their pagan gods. Instead, when they mention the name of their god, they have in mind the Creator of the world. Even though they refer to a duality (or trinity) of powers, this form of Avodah Zarah, called "Shituf" (worshipping another god along with Hash-m), is permitted to a Nochri (but not to a Jew). Rabeinu Tam adds that even if the Nochri uses in his oath the same word that Jews use to refer to Hash-m, such a word cannot be considered the "name of a pagan god" even if the Nochri does not have in mind the One G-d.
There is a difference between the two reasons of Rabeinu Tam's ruling. According to the first reason, entering a partnership with a Nochri remains prohibited even nowadays. According to the second reason, entering a partnership with a Nochri nowadays is permitted.
(c) The RAMBAN permits both entering a partnership with a Nochri and accepting a Nochri's oath in court. He explains that Avuha d'Shmuel did not actually prohibit the formation of a partnership with a Nochri on Halachic grounds. He merely advised against entering such a partnership. One who follows Avuha d'Shmuel's advice acts with "Midas Chasidus"; one who does enter such a partnership, or accepts an oath from a Nochri, transgresses no prohibition. (According to the Ramban, the verse quoted in the Gemara, "Lo Yishama Al Picha" (Shemos 23:13), prohibits only a Jew's mention of pagan gods.)
HALACHAH: The TUR (CM 182) rules in accordance with Rabeinu Tam's lenient view that one is permitted to accept an oath from a Nochri.
With regard to entering a partnership with a Nochri, most Rishonim (cited by the BEIS YOSEF CM 182) permit it. However, the SHULCHAN ARUCH himself (OC 156) writes that one should be careful not to enter a partnership with a Nochri, lest he cause the Nochri to make an oath in the name of his Avodah Zarah. The REMA there, however, says that the practice is to be lenient, in accordance with the view of Rabeinu Tam.