We learned in the last Perek (chapter) that if somebody borrows an item, he is responsible for any damage that happens to it, even if it was an accident and even if he could not have done anything to prevent it. He borrowed it, and therefore took responsibility for the item. This Mishnah is going to tell us there is an exception to the rule that a borrower is not automatically responsible for anything that happens to the item he borrows. There is an instance, a situation, where he is not responsible.
The Mishnah says that somebody borrows a cow and also borrows the owner along with it. In other words, when he borrows the cow, he asks the owner for a favor: to do work for him without being paid, and the owner agrees. The work the owner of that cow is going to do can have nothing to do with the cow; we will see what happens. It could be any type of work, not necessarily work related to that cow. Or, when he borrows the cow, he hires the owner along with it. Or he borrows or hires the owner first, and then afterward, while the owner is working for him, he borrows the cow. In any one of these cases, if the cow dies, even if the owner is not working for him at the time the cow dies, the borrower is exempt from paying for it. The borrower would not be responsible for paying for the cow that dies because the owner was working for him at the time he borrowed the cow. This is the fundamental point here: if the owner of the cow was working for the borrower at the same time that he borrowed the cow, he would not be responsible. Why? As the Pasuk (verse) says, “If the owner is working with him, then the borrower does not pay.” This Pasuk teaches us that if the animal’s owner was working for the borrower when he borrowed the cow, the borrower would not be responsible for paying for any damage or loss.
That is what we see here: if there is any overlap between borrowing the cow and the owner coming to work for the borrower in some capacity, whether the owner was there first and then the cow was borrowed, or they both came at the same time, the borrower would not be responsible for something that happens to the cow. That is what we learn from this Pasuk. But if he first borrows the cow and then afterward hires or borrows its owner, and the cow dies, the borrower would be obligated to pay for the cow. At the time of the borrowing, the owner of the cow was not working for the borrower. That crucial instant—the moment the borrowing of the cow was happening—is what matters. The owner was not working; he came on board maybe afterward. He became hired later on. In that case, the borrower would be responsible for the cow that dies, as the Pasuk says: Shene'emar (as it is stated), Be'alav ein imo, shalem yeshalem: if the owner is not working with the cow at that time that it's borrowed, then the borrower surely pays. He has to pay as long as he does not have the owner of the cow working at the same time, at that crucial moment when the borrowing started. Then the borrower would still be responsible to pay compensation for this cow that dies.