1) HOW THE LION'S CLAW BECAME LODGED IN THE BACK OF THE OX
OPINIONS: The Gemara discusses a case in which a lion entered a herd of oxen, and later a lion's claw was found lodged in the back of an ox. Rav says that we do not suspect that the lion attacked the ox and rendered it a Tereifah. Although most lions tend to attack oxen, when they attack they usually do not lose their claws in the process. Rather, we assume that the ox scratched its back against a wall and a lion's nail that happened to be in the wall become lodged in bovine's back.
The Gemara asks that the same logical process should be used to explain that the lion did attack. Although most oxen tend to scratch their backs against walls, they usually do not end up with a lion's nail lodged in their backs! We should assume, therefore, that a lion attacked the ox! The Gemara answers that since both possibilities are equally logical, Rav reverts to his ruling (unlike Shmuel) that we do not forbid an animal that is a Safek Derusah.
How exactly did a lion's nail become lodged in the back of an ox as it scratched itself against a wall?
(a) RASHI (DH Nis'chachech) writes that the ox was simply scratching itself on the wall, and there was a lion nail that had become lodged in that spot in the wall.
TOSFOS (DH Rov Arayos) has difficulty with the Gemara. If a lion has a tendency to attack, then all of the oxen in the herd should need to be examined for lion scratch marks (see RASHBA).
(b) Tosfos quotes RABEINU TAM who explains the Gemara's discussion in an entirely different manner. When the Gemara says that most lions are Dores, it means that most lions are healthy, and therefore are Dores. The Gemara says further that most lions who are healthy and who are Dores do not lose their nails. How, then, did the nail become lodged in the back of the ox? Rabeinu Tam explains that it must be that a sick lion was lying next to the wall which the ox leaned against, and the ox scratched its back against the sick lion's foot, causing the nail to lodge into its back. The Gemara responds that although most oxen scratch their backs against walls, they do not do so in a way in which their backs will meet up with the foot of a sick lion! Rather, the fact that there is a claw in the back of the ox indicates that the ox was attacked. The Gemara says that since both scenarios are within the realm of possibility, the ox is considered a Safek Derusah.
The SHITAH MEKUBETZES clarifies the opinion of Rabeinu Tam. Rav is saying that an odd phenomenon occurs. On one hand, a healthy lion seemingly attacked this ox. On the other hand, healthy lions who attack do not lose their claws. Since there is no clear reason for why this ox should have a lion's claw in its back, we say that it is possible that it came about because the ox scratched its back near a sick lion's paw. The Gemara responds that this, too, is implausible.
The LEV ARYEH answers the question of Tosfos on Rashi's explanation as follows. There is another case in which there would be no need to examine any of the oxen for claw marks (besides the case of the ox with the claw in its back). The Gemara itself says that even according to Shmuel -- who says that a Safek Derusah is forbidden -- in a case in which a lion sits down peacefully among the oxen and is quiet (and the oxen are also quiet), we do not assume that the lion attacked the animals. According to Rashi, this is the case that Rav is discussing. However, one of the oxen was found to have a lion's claw protruding from its back. The anomaly of a claw in its back is cause for greater inspection of the ox. None of the other oxen need to be examined, though, since the lion is observed to be resting peacefully among the herd. (Y. MONTROSE)
2) SELLING AN UNRECOGNIZABLE "SAFEK ISUR" TO A NOCHRI
OPINIONS: The Gemara discusses a case in which a hawk flew into a basket of birds. Each bird became a Safek Derusah, since perhaps each bird might have been attacked by the hawk and rendered a Tereifah. When the basket of birds was brought to Shmuel, he strangled them and threw them into the river. The Gemara questions Shmuel's actions. One of the Gemara's questions is why Shmuel did not allow the birds to be sold to a Nochri, as a Nochri is not forbidden from eating a possible Tereifah. The Gemara answers that Shmuel did not permit the birds to be sold to a Nochri because of the concern that the Nochri might subsequently sell the birds to a Jew who would not be aware that they were possibly Tereifos and he would eat a Safek Isur d'Oraisa.
The Gemara obviously refers to a case in which a Jew would not recognize the Isur. If the fact that the birds were Safek Derusos was clearly recognizable, then a Jew would not buy the birds in the first place and, presumably, Shmuel would have permitted them to be sold to a Nochri.
Does the same ruling apply to a case of a Safek not caused by an actual event, but by a doubt in the Halachah? For example, when two authorities disagree about whether a certain animal is a Tereifah, is one prohibited from selling the animal to a Nochri?
(a) The TERUMAS HA'DESHEN (#178) discusses a case in which a bear (that was known to be relatively friendly) jumped on an ox twice, and neither animal made the type of loud noises that bears and oxen usually make when they are involved in a fight. The Terumas ha'Deshen initially suggests that the ox is permitted, but he concludes that the ox may not be eaten. However, he permits the ox to be sold to a Nochri. He explains that this case differs from the case in Pesachim (40b) in which wheat sank in a river (and was recovered) and Rava prohibited selling it to Nochrim since they might sell it to Jews who would not know that the grain is Chametz and might use it on Pesach. The Nochri who buys the ox might sell it to another Nochri, and even if he sells it to a Jew, it is possible that the Halachah follows the ROSH in Chulin (3:40) who says that a bear does not render an ox a Derusah. The Terumas ha'Deshen quotes a similar ruling from the OR ZARU'A as recorded by the MORDECHAI in Pesachim (ibid.). The Or Zaru'a says that in a case in which the wheat that sank was the subject of an argument between Mar Ukva and Shmuel, it would be permitted to sell it to Nochrim, because of the same logic that perhaps the Nochri will sell it to another Nochri, and even if he sells it to a Jew, perhaps the Halachah is like Shmuel who says that such wheat is not Chametz.
The Terumas ha'Deshen clarifies his opinion further. Since selling to a Nochri an item that is an unrecognizable Vadai (definite) Isur is only Asur mid'Rabanan, when the item is only a doubtful Isur it should be permitted (because of the principle that Safek d'Rabanan l'Kula). The opinion of the Terumas ha'Deshen is recorded by the REMA (YD 57:21).
(b) The SHACH (YD 57:51) disagrees with the conclusion of the Terumas ha'Deshen for a number of reasons. The Terumas ha'Deshen himself writes at the end of his responsum that the issue remains in doubt ("Tzarich Iyun"). Moreover, the Or Zaru'a may have ruled the way he did because he maintained that the Halachah follows the view of Shmuel and Mar Ukva's opinion was only a stringency. The case of the Terumas ha'Deshen is different, because the Halachah follows the opinion that a bear does render an ox a Derusah. Finally, these words of the Or Zaru'a are not found in our texts of the Mordechai.
Therefore, the Shach writes that although one may rely on the Terumas ha'Deshen's ruling in the specific case of the Terumas ha'Deshen (the case of a bear and an ox), one may not use his logic in general to sell an unrecognizable Safek Isur to a Nochri, because there are many other issues involved (see Shach at length). The Shach concludes that his opinion also seems to be the opinion of the Rema and other Acharonim who record the Terumas ha'Deshen's ruling only in this specific case, but not in other cases of an unrecognizable Safek Isur. (Y. MONTROSE)