Bava Kamma, Chapter 10, Mishnah 6. In this mishnah, we will discuss the limitations regarding the location where one may return stolen property or repay a debt.
The language of the mishnah: "Hagozel es chaveiro, o shelavah heimenno, o shehifkid etzlo beyishuv - lo yachzir lo bamidbar". The mishnah lists three cases:
"Hagozel es chaveiro" - One who robs his fellow.
"O shelavah heimenno" - Or borrowed money from him.
"O shehifkid etzlo" - Or an item that was entrusted to him for safekeeping.
In all these cases, if the act took place "beyishuv" - in a populated area where there is a rule of law and it is relatively safe - then "lo yachzir lo bamidbar" - he may not return it to him in the wilderness: The robber cannot force the victim to accept the returned item in the wilderness, nor can the borrower force the lender to accept the repayment of his debt there.
The reason for the ruling:
The wilderness is a place of danger. Robbers and bandits are found there, and it is not a safe place to receive money. Therefore, the lender or the victim can say: Do not give me the money here, lest it be stolen; give it to me in a safe place, back in a populated area, and until then the responsibility rests on you.
The practical difference:
When the victim refuses: The robber said, "Here is the watch I pickpocketed from you, take it back," and the victim replied, "You must guard it and bring it safely to the city, and I am not taking responsibility for it yet." If the robber nevertheless pushed the watch into the victim's pocket and said, "I am done with this watch" - and the victim was subsequently robbed, these are circumstances beyond his control. In such a case, it is considered as if the robber never returned the stolen item, and he must give him a new watch or its monetary value.
When the victim agrees: The robber argued, "Take this from me now, because who knows if I will have another opportunity to return it to you, and perhaps I will change my mind." Although the victim initially objected, he finally relented and said, "Fine, I will take the watch." Since he agreed to accept it, if robbers later attacked him on the way and took the watch from his hand, the robber is exempt, because he returned the watch and the other accepted it. This is the central point of the mishnah.
The second part of the mishnah - "Al menas latzeis bamidbar":
Reuven and Shimon are about to execute a loan, and in the course of their conversation, one mentions that he is traveling abroad and his route passes through the wilderness, and his friend replies that he is also making his way there. Afterward, they execute the loan. It was never explicitly stated that the repayment would take place in the wilderness, but since they discussed the wilderness, it is implied that it will be permissible to repay the loan there, and the mishnah teaches that this is indeed effective.
The mishnah is not introducing a case where the borrower explicitly stipulated, "I am borrowing from you on the condition that I can repay you in the wilderness," and the lender agreed. In such a case, it is simple and clear that he may repay his debt there. The novelty of the mishnah is that even when they merely conversed about their shared journey to the wilderness and did not discuss the location of repayment at all, the context speaks for itself, and even without it being stated explicitly, it is clear and agreed upon that the loan can be repaid in the wilderness.
The mishnah expresses all this in a few words: "Al menas latzeis bamidbar - yachzir lo bamidbar" - At the time of receiving the money, the borrower said that he, too, was making his way to that place, via the wilderness. From now on, he is permitted to return the money to him in the wasteland, and say: I have repaid my debt to you, and if the money is stolen from you afterward, it is no longer my responsibility.
In summary: In this Mishnah we learned that a stolen item, a loan, or a deposit made in a settled area may not be returned in the wilderness, due to the danger of the location, and the responsibility remains on the robber or borrower until he returns it in a safe place. If he forced the owner to accept the item and it was lost due to circumstances beyond his control, he is liable; but if the owner willingly accepted it, he is exempt. We also learned that when the parties mentioned at the time of the loan that they would be traveling together to the wilderness, even without an explicit condition, this is considered an implicit agreement that the debt may be repaid there.