Inference: This shows that the Halachah follows the opinion who says that a renter is [liable] like a Shomer Sachar.

Support: It is proven like this in Yevamos (66b. It says a renter is liable for theft or loss) and below (97a) regarding Mereimar bar Chanina, who rented a mule to people of Bei Chuzai. (One version says that it was stolen, and Rava obligated them to pay. The Gemara infers that the Halachah is that a renter is like a Shomer Sachar.)

Observation: We could have said that this teaches unlike Shmuel, who said in Shevuos (25a) that Shevu'as Bituy applies only to something that can occur in the future...

However, he is exempt for a [false] Shevu'ah that Ploni threw a rock to the sea, for he cannot swear that he will throw;

Here, he is liable for a Shevu'ah that Ones occurred, even though it does not apply to the future!

Question - Citation (Gitin 29a - Mishnah): If one told [his Shali'ach to give the Get, and] "take item Ploni from her", [the Shali'ach] may not send it with someone else [because the husband does not want someone else to handle his item]!

Answer: Even though one may not deposit with someone else, doing so does not obligate him to pay.

Suggestion: Abaye holds that R. Yochanan obligates because he deviated from the owner's intent. Therefore, he is liable for all Onesim, even for Onesim that were proper to come in the Reshus of the first Shomer.

Rejection: If so, what was Abaye's challenge to Rava, that R. Ami should tell R. Aba 'the angel of death would have killed it no matter where it was!'?

Since he deviated from the intent of the cow's owner, he is liable even for Onesim that would have come in his Reshus! Therefore [R. Ami] needed to answer that he lent with the owner's permission!

Explanation: Rather, the reason is because it is considered as if he specified to him that if he will deviate from his intent, e.g. he will hand it over to someone else, it will be as if he was negligent...

... And any Ones that occurs to it, that we can attribute that had he not handed it over to someone else, it would not have occurred, he is liable for it.

E.g. if it died in the house of the second Shomer, we can attribute that the hot air in that house killed it;

Perhaps if it were in the house of the first Shomer, it would not have died, for some houses are healthier than others.

This is like one who was negligent with it, and it went out to the swamp, which is a good pasture, and it died. He is liable according to Abaye, who says that the hot air in that house killed it.

Also according to Rav, if he handed it over it to a Cheresh, lunatic or child and it died in their Reshus, he is liable for this reason.

Distinction: When he was not negligent with it, e.g. according to Rav he handed it over one with understanding, or he locked in front of it properly and it went out to the swamp, or he himself led it to the swamp, and it died there, he is exempt;

However, if he did not lock in front of it properly, even though he was negligent, if it died there, he is exempt, since even had he locked in front of it properly, it would have died there.

Even according to the opinion that the beginning was negligence and the end was Ones he is liable, this is only in a case like [coins that a Shomer put in] a shack of willow branches. (This is guarded from thieves, but it is negligence regarding a fire, for it is prone to burn.) It is possible that had he not been negligent at the beginning, the Ones of theft would not have occurred.

Source: It is proven like this below (78a). A Mishnah says that if one rented a cow to take it in the mountain and he used it in the valley and it slipped, he is exempt. If it became overheated, he is liable.

Question: According to the opinion that when the beginning was negligence and the end was Ones, he is liable, even when it slipped, why is he exempt? The beginning was negligence, regarding overheating, and the end was Ones, regarding slipping!

Answer: Rather, it is because even had he taken it in the mountain, all the more so it would have slipped.

Conclusion: Therefore (since Abaye holds that R. Yochanan holds that any deviation from the owner's intent is considered negligence, and he is liable for any Ones that we can attribute that had he not handed it over to another, it would not have occurred), he properly challenged Rava.

And even according to the opinion that the beginning was negligence and the end was Ones, he is exempt, here, when he gave it to another Shomer, he is liable;

There, regarding a shack of willow branches, the Ones was not prone to occur until the thieves came;

However, here, it is revealed that the hot air and that place were more dangerous to kill this animal. The illness began once it came there.

Support: Abaye said so below, that even according to the opinion that [when the beginning was negligence and the end was Ones,] he is exempt, here he is liable.

Question: This is difficult for Rav!

Answer #1: It mentioned his children for a Chidush. One might have thought that one deposits with intent also for the minor children, for it is normal that sometimes one hands over his items to his minor children. The Mishnah teaches that this is not so.

Answer #2: It mentioned his children, and did not say children Stam, because we need to infer that if they are adults, this is like Shomerim normally do, and it is permitted, for one deposits with intent for adult children;

However, one may not hand it over to other adults, even though he is not liable for doing so.

Consequence: Therefore, when the first Shomer can swear about the Ones, or witnesses saw the matter, he is exempt;

And even if he handed it over to a Cheresh, lunatic or child, and it died in their Reshus [he is exempt], for it would have died even in the house of the first Shomer, for the angel of death would have killed it no matter where it was.

Rava holds that this is R. Yochanan's reason, unlike Abaye, who says that it is because "I do not want [others handling my object]."

Pesak: The Halachah follows Rava. This is unlike R. Chananel, who rules like Abaye.

Explanation: Now, it was not negligence to take it up.

Explanation: This is fine for Rava, who says that the angel of death [would have killed it no matter where it was]. He need not establish that it was a good pasture. Therefore, if he took it up a steep mountain and it fell, he is liable for taking it up;

This is even though it fell Bal Korcho (against his will), i.e. he grabbed it and it descended.

The Reisha, which teaches "if it ascended, he is exempt" discusses when he grabbed it and it ascended. Also the falling was when he grabbed it and it descended, like in the Reisha;

Distinction: However, according to Abaye, who establishes that it was a good pasture, he was not negligent in the ascent. He is liable because he was negligent in its fall. The case is, he could have grabbed it, and he did not grab it;

If so, also in the Reisha, even if he grabbed it and it ascended, why is he exempt? He should be liable for the fall. He should have guarded it lest it fall!

Presumably, "it fell" in the Reisha is like "it fell" in the Seifa, when he could have grabbed it.

Explanation (cont.): We answer that in the Reisha, the case is that he grabbed it and it descended, similar to "it ascended", which is when he grabbed it and it ascended. It is unlike the falling in the Seifa.

Question: Why did the Reisha say "it ascended", and the Seifa says "he brought it up"? There is no difference between taking it up willingly, or Bal Korcho! (Since it was a good pasture, he was not negligent);

It should distinguish only in falling. If he grabbed it and it descended, this is Ones. If he did not grab it, he is liable!

Answer: The Reisha says "it ascended" to reveal that [also] the fall was Bal Korcho;

The Seifa says "he brought it up" to reveal that the fall was in a way that he could have grabbed it, and he did not grab it, like "he brought it up", which was in his power.

Question: In the Seifa, since we discuss when he could have grabbed it, why does it discuss a good pasture?

Even if it was not a good pasture, he was not negligent in the ascent, since he could have guarded it from falling!

Answer: Since this ascent was not needed for the animal, he was negligent. He should have been concerned lest he forget and not guard it from falling. Therefore, if it died [even without falling] he would be liable.