Explanation #1: Rashi explains that Rebbi Yishmael's reason is because (he can say that) 'When I declared my pit Heker, it was in order that I should not be held liable for its damages ...

Inference: ... implying that had he initially dug it next to the R'shus ha'Rabim, he would be Chayav according to everybody (even according to Rebbi Yishmael).

Refutation #1: But his is not what the Gemara seems to be saying..

Refutation #2: Moreover, the Gemara will shortly say that had he not dug it as a foundation (for his house), he would be Chayav, and Rabah establishes it according to Rebbi Akiva - implying that according to Rebbi Yishmael, he would be Patur.

Explanation #2: Rebbi Yishmael's reason is because he can say to him (the owner of the ox) 'What is your ox doing in my pit'?

Reason: ... since it should not have come so close to my R'shus that it could fall into the pit!

Clarification: 'Kulah' is La'av Davka, since it is confined to the Reisha and the Seifa, from which the Gemara asked ...

Clarification (cont.): ... whereas the Metzi'asa, which says 'bi'Reshus ha'Yachid u'Pascho li'Reshus ha'Rabim, Chayav', does not go like Rebbi Yishmael.

Clarification: Now, it all goes according to both opinions - the Reisha, where he declared Hefker neither his R'shus nor his pit, and the Seifa, where he widened the pit.

Clarification (cont.): Only according to Rebbi Yossi b'Rebbi Yehudah, who requires 'Harchakah' (keeping a distance) it will not go like Rebbi Yishmael.

Question: How did he know that, considering that his son died from thirst?

Answer: Nevertheless, it was not befitting for children to die in the very same thing for which he went to so much trouble.

Yerushalmi: In Shekalim (Perek 5, Halachah 1 [See there]), the Yerushalmi records that an angel in the image of Rebbi Chinana, appeared and saved his daughter.

Explanation #1: In 'Osin Pasin' (Eruvin, Daf 22a & 22b) the Gemara explains 'la'Resha'im' to mean 'to destroy them from the World to Come' ...

Explanation #2: ... whereas in Cheilek, it interprets it for the good?

Reconciling the Two: There where they will not ultimately do Teshuvah, it is for the bad, and where they will, it is for the good.

Implied Question #1: The Gemara might just as well have presented a case where the animal fell backwards, since, according to Rav, he is only Chayav if it fell forwards, where there is foul air ...

Implied Question #2: ... or where the pit is wider than it is deep, where there is no foul air, as the Gemara will say later (on Daf 51b) ...

Answer: ... only the Gemara mentions just one of the distinctions.

Clarification: It must be speaking where the animal tripped on the upper protrusion and banged itself on the bottom of the pit ...

Clarification (cont.): ... since if it had banged itself on the upper protrusion, Rav would concede that he is Chayav ...

Precedent: ... as we find in the case of 'His stone, his knife or his bundle (on Daf 3a) in connection with which the Gemara writes 'If he declared it Hefker, according to both Rav and Shmuel, that is 'Bor'

Reason: And the reason for this is because the source of the knock belongs to him.

Question: There where the animal tripped on the upper protrusion and banged itself on the bottom of the pit. Shmuel concedes that he is Patur, seeing as it is the public ground that wounded it ...

Proof: ... as is evident later (on Daf 53a), where Shmuel establishes the case of 'Behind the pit, he is Patur' - where it tripped on the edge of the pit and fell behind it?

Answer #1: The Gemara here is speaking where he made a protrusion eight Tefachim tall, around which he dug a pit five Tefachim deep - and where he tripped on the protrusion and banged himself at the bottom of the pit ...

Answer #2: Or alternatively, Sh'muel only declares him Patur later, a. because the animal fell due to the noise of the banging ...

Reason: ... which caused him to fall, and b. because it was not his property that caused the knock, since it banged itself on the ground outside the pit.

Question: And one cannot ask that the owner of the pit ought to be Chayav at least for half the damage that it caused - and even for all the damage ...

Reason: ... seeing we establish it like Rebbi Nasan, who holds that 'Whatever one cannot claim from one Mazik, one claims from the other'?

Answer: Shmuel holds one can never hold the owner of the pit liable, even according to Rebbi Nasan, unless it alone causes the animal to fall, and it is only if it does that the owner is Chayav if the Nizak bangs itself, or if it causes the damage even though it did not cause the fall.

Answer (cont.): But if it partially causes the animal to fall, the owner is Patur, in the event that it then bangs itself on public ground.

Conclusion: And this explanation justifies the Gemara later (Ibid.) which implies that if the animal tripped on a stone and fell into the pit, the owner of the stone (alone) is Chayav, even though he did not dig the pit.

Clarification: This means that the Beraisa first makes the statement, then explains from where it learns it.

Clarification: The Gemara in Chulin, Perek Eilu T'reifos (Daf 51b & 5a) states that if the animal stands up, it does not require twenty-four hours, though it does need `to be examined and that even that is not necessary if it walks.

Clarification (cont.): It is unclear from there however, as to whether it needs examination if it survives twenty-four hours

Halachah le'Ma'aseh: The B'hag however, seems to hold that it does, since he says that we are not conversant in the examination ...

Halachah le'Ma'aseh (cont.): ... and that it therefore needs to survive twelve months.