As had the tanna taught the case of a found item alone, I would say that it is only in the case of a found item that the Sages imposed an oath upon him, as in that case one can rationalize his actions and say: The other party, the one who in fact found the item, is not losing anything by not keeping all of it, as it was not his to begin with. I will go seize it from him and divide it with him. But in the case of buying and selling, where that cannot be said, say that the Sages did not impose an oath upon him.

And had the tanna taught the case of buying and selling alone, one might say that it is specifically in this case that the Sages imposed an oath upon him, because he could rationalize his actions, saying to himself: The other party gave money to the seller and I gave money to the seller; now that I need it for myself, I will take it and let the other one go to the trouble to buy another item like the first item. But in the case of a found item, where that cannot be said, say that the Sages did not suspect that he seized an item that did not belong to him, and therefore there is no need to impose an oath upon him. Therefore, both cases are necessary.

The Gemara asks: How can the mishna be referring to a case of buying and selling? But let us see from whom the seller took the money. Obviously, the one who gave him the money is the one who bought it. The Gemara answers: No, it is necessary in a case where he took money from both of them. He accepted the money willingly from the one to whom he wanted to sell the item, and he received the money against his will from the one to whom he did not want to sell the item, and I do not know who is the one from whom he took it willingly, and who is the one from whom he received it against his will. Consequently, the matter is clarified by means of an oath.

§ The Gemara suggests: Let us say that the mishna is not in accordance with the opinion of ben Nannas, as, if it were in accordance with the opinion of ben Nannas, doesn’t he say that an oath is not administered to two parties in court when one of them is certainly lying?

As it is stated in a mishna (Shevuot 45a): With regard to a case where a man said to his laborer: Go to the storekeeper and he will give you food in lieu of your salary, and sometime later the laborer claimed that the storekeeper did not give him anything while the storekeeper claimed that he did, the Rabbis say: The storekeeper and the laborer must each take an oath to support their claims, and the employer must pay them both. Ben Nannas says in response: How can you allow these people, i.e., the laborer, and those people, i.e., the storekeeper, to come to take an oath in vain? Since one of them is definitely lying, the Sages would not impose the taking of an oath that by definition must be false. Similarly, in the case of the mishna here, since the found item is divided between the parties in any case, according to the opinion of ben Nannas they should receive their portions without taking an oath.

The Gemara rejects this suggestion: It is even possible for you to say that the mishna is in accordance with the opinion of ben Nannas. There, in the case of the laborer and the storekeeper, an oath is certainly taken in vain, as it is clear that one of them is lying. Here, there is room to say that there is no oath taken in vain. Say that they are both taking an oath truthfully, as they lifted the item together, and therefore each of them owns half of it. In this case, ben Nannas would agree that they both take an oath.

The Gemara suggests further: Let us say that the mishna is not in accordance with the opinion of Sumakhos, as, if it were in accordance with the opinion of Sumakhos, doesn’t he say the following principle: In a case of property of uncertain ownership, the parties divide it without taking an oath.

The Gemara rejects this suggestion: Rather, what opinion does the mishna follow? Does the mishna follow the opinion of the Rabbis, who disagree with Sumakhos? Don’t they say that in a case of property of uncertain ownership the burden of proof rests upon the claimant? In the case of the mishna neither side offers proof.

The Gemara answers: What is this comparison? Granted, if you say that the mishna is in accordance with the opinion of the Rabbis, there is room to distinguish between two cases: There, in the case of property of uncertain ownership, where both parties are not grasping the property, the Rabbis say that the burden of proof rests upon the claimant since the one with possession of the property ostensibly has the right to that property. Here, in the case of the mishna, where both are grasping the property and neither has exclusive possession of the item, they divide it with the proviso that they take an oath.

The Gemara continues to state its proof that the mishna is not in accordance with the opinion of Sumakhos: But if you say that the mishna is in accordance with the opinion of Sumakhos, how do you resolve the following contradiction: Now, if there, in a case where they are not both grasping the property, they nevertheless divide it without taking an oath, here, where they are both grasping the property, is it not all the more so that they should divide it without taking an oath?

The Gemara rejects this suggestion: You may even say that the mishna is in accordance with the opinion of Sumakhos. When Sumakhos states that in a case of property of uncertain ownership, the parties divide it without taking an oath, that is in the case of an uncertain claim and an uncertain claim, i.e., when the circumstances are such that neither party can state definitively that he is entitled to the property. But in a case of a certain claim and a certain claim, where each party states definitively that he is entitled to the property, Sumakhos does not say that they divide the property without taking an oath.

The Gemara asks: And according to the opinion of Rabba bar Rav Huna, who said that Sumakhos says that even in a case of a certain claim and a certain claim the parties divide the property without an oath, what is there to say to establish the mishna in accordance with the opinion of Sumakhos?

The Gemara answers: You may even say that the mishna is in accordance with the opinion of Sumakhos. When Sumakhos says that property of uncertain ownership is divided, he is referring to a case where the litigants have a financial association with the item independent of their claims to it. But where the litigants do not have a financial association with the item beyond their claims, they do not divide it without taking an oath.

The Gemara asks: But is it not an a fortiori inference? If there, in a case where this Master has a financial association with the item, and that Master has a financial association with the item,