Explanation #1: Rashi explains that if he is going according to the Rabbanan of Rebbi Nasan in Perek ha'Parah (on Daf 53a) who say, in connection with the case where one ox pushes another ox into a pit, that if it is a Tam, the owner pays half and the owner of the pit is Patur.

Explanation #1 (cont.): So we see that, there where one cannot exact payment from the owner of the ox, one cannot exact payment from the owner of the pit, even though the damaged ox was found in his pit.

Explanation #1 (concl.): In that case, it is obvious that one cannot claim for the Emurim from the Basar.

Inference: This implies that the ox is considered as having performed the entire damage, and the pit, nothing at all, which is why a Shor Mu'ad pays in full and a Shor Tam, half.

Conclusion: And that is why the Gemara can extrapolate only from the Tam and not from the Mu'ad.

Proof: In fact, that is what Rashi specifically says later in Perek ha'Parah (Ibid. DH 'Es'), where he writes - 'But the Rabbanan, who go after the beginning, hold that the ox performed the entire damage, which explains why the Mu'ad pays in full, and the Tam, half, and the other half, the owner of the damaged ox loses.

Question #1: The Ri asks how one can extrapolate that one cannot claim for the Emurim from the Basar, from the fact that, in the case of the Tam, the owner of the damaged ox, who receives nothing from the owner of the pit, loses half?

Question #1 (cont.): ... seeing as that is because the pit did not perform any damage, whereas in the case of the Shelamim, where the Basar performed damage just like the Emurim, there where one cannot exact payment from the Emurim, one will exact payment from the Basar?

Reason: ... since, seeing as the Gemara has not yet come up with the S'vara 'I found my ox in your pit', the Gemara must currently hold that where two entities damaged, each one is considered as having performed the entire damage ...

Reason (cont.): Because if each one only performed half the damage, why, according to Rebbi Nasan, should the owner of the pit pay three-quarters, which is more that the damage that he performed? And without a good reason, we will not say it ('I found your ox ... '), as is evident in ha'Parah.

Question #2: Furthermore, from where does the Gemara know that according to the Rabbanan, the Tam pays a half and the pit is Patur? Perhaps by a Tam, the owner of the pit too, pays a half, and when the Rabbanan say that the owner of the pit is Patur, they are speaking about a Mu'ad?

Explanation #2: The Ri therefore explains that when the Rabbanan say that the owner of the ox pays half and the owner of the pit is Patur, they mean that if the ox is a Mu'ad, the owner pays half, and if it is a Tam, a quarter, and that either way, the owner of the pit is Patur ...

Reason: Because the Torah only declares a pit Chayav where the animal falls in automatically, since the Pasuk writes "And an ox ... falls in". But where others push it in, the owner of the pit is Patur.

Explanation of Statement: And what the Gemara means is as follows: 'They say that if one cannot exact payment from the owner of the pit, one does not exact payment from the owner of the ox', even though they hold that each one is considered as having performed the entire damage ...

Explanation of Statement (cont.): ... in which case it is obvious that one cannot claim from the Basar for the Emurim; So what is Rebbi Aba coming to teach us?

Question: From where does the Gemara know that when the Rabbanan say that the owner of the ox is Chayav, they do not mean that he is Chayav to pay the entire amount?

Answer #1: Because if Rebbi Nasan and the Rabbanan were arguing over the payment of the ox, they ought to have said so, and since they did not, it is clear that the Rabbanan concede to Rebbi Nasan in that point.

Answer #2: Moreover, if the Rabbanan would require the owner of the ox to pay the entire amount, then Rebbi Nasan should have stated that he only pays half.

Clarification: It is only by Bor that the Gemara rules that he has to pay ...

Clarification (cont.): In spite of the fact that each one is considered as having performed the entire damage, it is feasible to draw a distinction between Shor and Bor for this reason.

Observation: However, since the Gemara knows the reason of 'I found my ox in your pit', it could even hold that each one is considered as having performed half the damage, as the Gemara will explain in 'ha'Parah' (Ibid.). Tosfos will elaborate there be'Ezras Hash-m.

Observation: Even though Rava explains the Mishnah with regard to the Din of Me'ilah, and does not establish it like Rebbi Yossi ha'Gelili, the current case must go according to Rebbi Yossi ha'Gelili.

Refuted Explanation: It would seem that he (Rebbi Yehudah) does not Darshen from the word "ve'Hu'ad" ...

Refutation: Since this "ve'Hu'ad" is not speaking about Eidus regarding stoning the animal, but about Eidus that turns it into a Mu'ad.

Correct Explanation: But rather from the Seifa of the Pasuk, which says "ha'Shor Yisakeil".

Proof: And so it seems from from the Lashon of the Gemara's Kashya 'But "ha'Shor Yisakeil" is written in connection with the conclusion of the Din?'

Explanation #1: They are arguing over where the field is designated for fruit but not for oxen, as is evident at the end of the Sugya (Daf 11a), where they argue over the Kashya of Rebbi Zeira and the answer of Abaye?

Observation: According to that, Rav Chisda could well have explained the Mishnah like Rebbi Elazar ...

Conclusion: ... and the text later, citing Rebbi Elazar, reads - 'Think it over; Does the Beraisa not argue?'

Text #2: But according to the text that reads 'Think it over; Does the Beraisa argue?', and subsequently 'But that Beraisa is speaking ... ', are all part of Rebbi Elazar's statement ...

Explanation #2: We will have to say that they are arguing where the field is designated both for fruit and for oxen.

Explanation #2: And what the Gemara means to say is 'Think it over, do they argue? But does the Beraisa not say ... ?' Consequently, we must say that they do not argue. 'And when does the Tana say ... '.

Conclusion: According to this text, the beginning of the Sugya does not conform with the conclusion, which states that they argue over the Kashya of Rebbi Zeira and the answer of Abaye.

Question #1: According to Rav Chisda, from where will we learn Keren according to Shmuel and all the current cases according to Rav?

Question #2: Furthermore, the Beraisa which states 'ke'she'Hizik, Chav ha'Mazik', which is superfluous and includes all of these, poses a Kashya on Rav Chisda (See Maharam)?

Answer: According to him too, there is a Yitur (something superfluous), since it could have said 'u'Reshus ha'Nizak ve'ha'Mazik Chayav', without adding 'ke'she'Hizik Chav ha'Mazik'.

Question: The Beraisa does however, pose a Kashya on Shmuel (See Maharam).

Implied Question: One cannot say the reverse - that the ox belonging to the Sho'el gored that of the owner, where he accepted to guard it from damaging but not from guarding it against damages ...

Answer: Because it is something that is not common.

Implied Question: And even though where he recognized that it is a goring ox, the Gemara says in 'Shor she'Nagach Arba va'Chamishah' that presumably, he accepts to guard it against goring and damaging others, but not against others damaging it ...

Answer: ... one cannot say that by a Sho'el, who undertakes to guard it properly.