Kommentar zu Bava Metzia 3:2

השוכר פרה מחבירו – and the renter/leasee stood and lent it (i.e., the cow) to another with the permission of the lender. But if the leaser had not given permission, we establish that a bailee who transferred [an object] to another bailee is liable.

If a man rented a cow from his fellow and lent it to another, and it died a natural death, the hirer must swear that it died a natural death and the borrower must repay [its value] to the renter.
Rabbi Yose said: “How can this one make business out of his friend’s cow? Rather [the value of the cow] returns to the owner.”
Mishnah two deals with the liability of a person who rents a cow and then subsequently loans the cow to someone else and the cow dies.
Mishnah three deals with a person who admits to having stolen or otherwise received money from one of two people but does not know from which one.
As we learned in the introduction to mishnah one, a renter is not liable to pay back the owner if the rented animal dies a natural death. In such a case he is allowed to take an oath and be exempt. The borrower, on the other hand, is liable to pay back the value of the borrowed animal even if it dies a natural death. In our mishnah a renter loaned the rented cow to a third party and then the cow died. The renter may take an oath that the cow died a natural death and he is exempt. The borrower, however, is liable to pay the value of the cow. Since he borrowed from the renter he must repay the renter.
Rabbi Yose claims that such a law allows the renter to make unfair profit from the cow that belongs to someone else. In his opinion the value of the cow should be paid from the borrower directly to the original owner. In other words, although the renter can exempt himself from paying by taking an oath, he does not thereby earn the rights to future benefits accrued from the animal.

ישבע השוכר – to the leaser

שמתה כדרכה – and is exempt [from payment], for the renter is exempt from unavoidable accidents.

והשואל – who is liable for unavoidable accidents , pays the renter, with an oath that he swears to the landlord.

אמר רבי יוסי: כיצד הלה עושה סחורה וכו' – And the Halakha is according to Rabbi Yosi.