MISHNA: With regard to one who exchanges a cow for a donkey, such that by virtue of the cow owner’s act of acquisition on the donkey, the donkey’s erstwhile owner simultaneously acquires the cow, wherever it happens to be located, and afterward the cow is found to have calved; and similarly, with regard to one who sells his Canaanite maidservant, with the acquisition effected by the buyer giving him money, and afterward she is found to have given birth to a child, who will be a slave belonging to his mother’s master, at times it is uncertain whether the offspring was born before or after the transaction. If this seller says: The birth occurred before I sold the cow or maidservant, and so the offspring belongs to me, and that buyer says: The birth occurred after I purchased the cow or maidservant, and so the offspring belongs to me, they divide the value of the offspring between them.

The mishna continues: There is a case of one who had two Canaanite slaves, one large, worth more on the slave market, and one small, worth less on the slave market, and similarly, one who had two fields, one large and one small. He sold one of them, and there was a dispute between the buyer and the seller concerning which one was sold.

If the buyer says: I purchased the large one, and the other one, i.e., the seller, says: I do not know which I sold; the buyer is entitled to take the large one.

If the seller says: I sold the small one, and the other one, i.e., the buyer, says: I do not know which one I purchased; the buyer is entitled to take only the small one.

If this one says: The large one was sold, and that one says: The small one was sold, then the seller takes an oath that it was the small one that he sold, and then the buyer takes the small one.

If this one says: I do not know which one was sold, and that one says: I do not know which one was sold, they divide the disputed amount between them.

GEMARA: The Gemara asks: In the first clause of the mishna, why do the two parties divide the value of the offspring between them? Instead, let us see in whose domain the offspring currently is. That person has presumptive ownership of the offspring, and the other person will be considered to be the one who is exacting property from another, and accordingly, the burden of proof rests upon him. Since he cannot prove his claim, he is not entitled to take the offspring.

The Gemara answers: Rabbi Ḥiyya bar Avin says that Shmuel says: The mishna is referring to a case where the calf is standing in the marsh, i.e., it is in the domain of neither the buyer nor the seller, and so neither one has presumptive ownership. And with regard to the maidservant also, this is a case where the child is found in an alley which does not belong to either the buyer or the seller.

The Gemara asks further: But even if the offspring is not in either party’s domain, establish it to be in the presumptive ownership of its original owner, i.e., the seller, as he certainly owned the offspring when it was still a fetus. And so the other person will be considered to be the one who is exacting property from another, and accordingly, the burden of proof rests upon him. Since he cannot prove his claim, he is not entitled to take the offspring.

The Gemara answers: In accordance with whose opinion is the ruling of this mishna, that the parties divide the value of the offspring equally? It is in accordance with the opinion of Sumakhos, who says: When there is property of uncertain ownership, the parties divide it equally without the need to take an oath.

The Gemara challenges this: Say that Sumakhos says his ruling when there is a conflict between an uncertain claim and an uncertain claim, as each party admits that his claim to the property is uncertain, but did he say his ruling when there is a conflict between a certain claim and a certain claim, as each party claims to be certain that the property belongs to him?

The Gemara offers two opinions concerning the ruling of Sumakhos. Rabba bar Rav Huna said: Yes, Sumakhos says his ruling even when there is a conflict between a certain claim and a certain claim.

Another opinion: Rava said: Actually, when Sumakhos said his ruling, it applies only where there is a conflict between an uncertain claim and an uncertain claim, but when there is a conflict between a certain claim and a certain claim, he did not say his ruling. And in order that the mishna not pose a difficulty, emend it to refer to uncertain claims and teach: This seller says: Perhaps the birth occurred before I sold the cow or maidservant, and that buyer says: Perhaps the birth occurred after I purchased the cow or maidservant.

The Gemara challenges Rabba bar Rav Huna’s opinion: We learned in the mishna: If this one says: I do not know which one was sold, and that one says: I do not know which one was sold, they divide the disputed amount between them.

Granted, according to the opinion of Rava, from the fact that the last clause of the mishna is referring to a case where there is a conflict between an uncertain claim and an uncertain claim, one can say that the first clause as well is referring to a case in which there is a conflict between an uncertain claim and an uncertain claim. But according to the opinion of Rabba bar Rav Huna, who said: Yes, Sumakhos says his ruling even when there is a conflict between a certain claim and a certain claim, there is the following difficulty: Now that the mishna teaches that even when there is a conflict between a certain claim and a certain claim Sumakhos says that the parties divide the disputed amount between them, is it necessary for the mishna to state that where there is a conflict between an uncertain claim and an uncertain claim the parties divide the disputed amount between them?

The Gemara rejects the question: If the difficulty is due only to that reason, there is no conclusive argument. One can say that the mishna taught the latter clause to shed light on the first clause, so that you will not say that the ruling in the first clause applies only where there is a conflict between an uncertain claim and an uncertain claim, but where there is a conflict between a certain claim and a certain claim the ruling in the first clause does not apply, and the disputed amount is not divided. To dispel this notion, the mishna teaches the last clause, which is referring to a conflict between an uncertain claim and an uncertain claim; and then by inference, the first clause must refer to a case where there is a conflict between a certain claim and a certain claim, and nevertheless, the parties divide the disputed amount between them.

The Gemara again challenges Rabba bar Rav Huna’s opinion: We learned in the mishna: If this one says: The large one was sold, and that one says: The small one was sold, then the seller takes an oath that it was the small one that he sold, and then the buyer takes the small one.

Granted, according to the opinion of Rava, who said that when Sumakhos says his ruling it applies only where there is a conflict between an uncertain claim and an uncertain claim, but when there is a conflict between a certain claim and a certain claim he did not say his ruling, it is due to that reason that in the clause in the mishna in which each party offers a certain claim, the seller takes an oath. But according to the opinion of Rabba bar Rav Huna, who said: Yes, Sumakhos says his ruling even when there is a conflict between a certain claim and a certain claim, why does the mishna rule that the seller takes an oath; the mishna should have ruled that they divide the disputed amount between them.

The Gemara answers: Sumakhos concedes that where there is a requirement for one of the parties to take an oath required by Torah law the disputed amount is not divided, as we will need to say below to resolve another challenge to Sumakhos’ opinion.

§ The mishna teaches: In a case of one who had two Canaanite slaves, one large, worth more on the slave market, and one small, worth less on the slave market, and the buyer and seller disagree as to whether it was the large slave or the small slave that was sold, the seller takes an oath that it was the small one that he sold, and then the buyer takes the small one. The Gemara asks: Why does the seller take an oath? An oath is required only when a defendant admits to part of the claim made against him, but in this case, that which the buyer claimed from the seller, i.e., the larger slave, the seller did not admit to at all, and that which the seller admitted to, i.e., the smaller slave, the buyer had not claimed from him.

And furthermore, with regard to the small slave, this is a case of: Here you are. The seller is not merely admitting that he is liable to give the slave in the future, but allows the buyer to take possession of the slave immediately. As Rav Sheshet explains on 4a, one who offers the disputed item immediately is not considered to be one who admits to part of a claim, and is exempt by Torah law from taking an oath.

And furthermore, one does not take an oath concerning a claim about slaves, but only concerning claims about movable property. For these three reasons, there should be no requirement to take an oath.

Rav said: The mishna is referring to a case where the buyer claims money from the seller, not a slave or a field; the buyer claims that he gave the seller money equal to the value of a large slave and the seller admits to having received money equal to the value of a small slave. And in the case of the field, the buyer claims that he gave the seller money equal to the value of a large field, and the seller admits to having received money equal to the value of a small field.

And Shmuel said: The mishna is referring to a case where the buyer claims he purchased a garment of a large slave, and the seller admits to having sold him a garment of a small slave. And in the case of the field, the buyer claims he purchased the sheaves yielded by a large field, and the seller admits to having sold him the sheaves yielded by a small field.