In the last Mishnah, we mentioned a storekeeper who swore and then collected on a claim. Here, we'll talk about a situation where we don't have enough evidence to know which side of the argument is right. Therefore, the Chachamim (the Sages) metaken (instituted) that we could decide the matter only based on who has the stronger claim, even though it's not foolproof. We make that person swear, and then he takes the money.
The Mishnah says: If a customer tells the storekeeper ... What that means is that the storekeeper put the produce outside the store, in the street, for the customer to bring home. Then the storekeeper told the customer, “Give me the money now. Give me the dinar (a bigger coin) that you owe me for the produce.” The customer responded, “I gave it to you. I handed it to you, and you already put it in your wallet, your money pouch.” In that case, we say the customer would swear that he had already paid the dinar, and he would take the produce home with him. We say that the customer's claim here is stronger. He is probably right. The storekeeper admitted that he agreed to sell the produce to the customer. Therefore, we assume that a money transaction—a handoff—happened right away.
Now we'll have the opposite case. If the customer gave the storekeeper the money and then said to him, “Give me the produce in the street that I paid for,” the storekeeper told him, “I already gave you the produce that you paid for, and you took it home. The produce in the street is mine.” That's something else. In this case, the storekeeper would swear that he had already given him the produce, and he would keep whatever was in the street, because the storekeeper's claim is considered stronger than the customer's. We assume that when the handoff of money happened, the produce was given over. Therefore, the storekeeper has the better argument here.
But Rabbi Yehuda disagrees. Rabbi Yehuda says, “Whoever has the produce in his possession has the upper hand.” The produce is outside the store in both cases. So we treat it as if it's out of the storekeeper's possession and in the customer's possession. Therefore, in both cases, the customer is considered to have the better claim, and he would swear and take the produce.
Another case: A customer tells the money changer, “Take this dinar, which is a bigger coin, and give me ma'ot instead. Give me a lower price. A lower breakdown of coins.” The money changer gave the coins to him. He took those coins and put them in the street in front of the customer. Then he told the customer, “Okay, now give me the bigger coin. Give me the dinar.” The customer replied, “I already gave you that big coin, and you put it in your wallet.” In that case, the customer would swear that he paid the dinar and take the money from the street. His claim is considered stronger than the money changer's.
But in the opposite case, if the customer gave the dinar to the money changer and then said to him, “Give me the change. Give me the ma'ot in the street that I paid you for,” the money changer tells him, “I already gave you the change that you already paid for, and you threw them into your wallet. The money in the street is different money, and that money is mine.” We say the money changer swears that he already gave him the change, and he takes the money from the street, since in this case the money changer's side is considered stronger than the customer's.
But again, Rabbi Yehuda disagrees. Rabbi Yehuda says, “It's quite uncommon for a money changer to give out money until he receives his money as payment.” In other words, people don't give change unless they first receive payment for the money they plan to give out. So what does the fact that the money changer took the money and put it in the street show? That he received the dinar he was planning on receiving. Therefore, in both cases, the customer's claim is better, and in both situations the customer would swear and take the money.