The Gemara discusses the basis for Rav’s explanation. Know that the mishna is referring to claims of monetary value, as it teaches in the latter clause that if the claimant said: I have a gold dinar in your possession, and the defendant responded: You have only a silver dinar, or a tereisit, or a pundeyon, or a peruta in my possession, he is liable to take an oath, as they are all of one type; they are all coins. Granted, if you say that the claim was for the value of a gold dinar, it is due to that reason that he is liable to take an oath, as he admitted to a part of the claim. But if you say that the claim was specifically for a dinar of gold, why is he liable? The claim was for gold, and he admitted to owing silver or copper.

The Gemara rejects this proof: Rabbi Elazar says: This mishna is referring to a case where one claimed that the defendant owes him a dinar of coins, i.e., coins worth a dinar. The claim was for specific coins, and not a monetary value. Since the claim concerned coins and not a specific weight of metal, and all coins are used for commercial transactions, all types of coins are considered of the same type. And it teaches us that a peruta is included in the category of a coin. According to this explanation, the language of the mishna is also precise, as it teaches: The defendant is liable to take an oath, as they are all of one type [min]; they are all coins. In other words, even a peruta is a type of coin.

The Gemara asks: And how would Rav, who holds that the claim in this case was for the value of a dinar, explain the fact that the mishna states: As they are all of one type; they are all coins? Why does it matter that they are all of one type? The Gemara answers that according to Rav, the reason the defendant is liable to take an oath is that because the claim is for the value of a dinar, all descriptions of monetary value based on different coins have one status under halakha [din]; they are all coins, and it is of no significance that they are made of different materials.

The Gemara asks: And concerning the opinion of Rabbi Elazar, shall we say that since he explains the latter clause in the mishna as referring to a specific item and not a value, in accordance with the opinion of Shmuel, then also with regard to the former clause, that states the claim must be for two silver ma’a, he apparently holds in accordance with the opinion of Shmuel, i.e., that it is referring to two actual ma’a, and not the value of two ma’a?

The Gemara rejects this suggestion: No, Rabbi Elazar explains that the latter clause of the mishna is referring specifically to actual items in accordance with the opinion of Shmuel, as it teaches explicitly: As they are all of one type; they are all coins. But the former clause can be interpreted either in accordance with the opinion of Rav or in accordance with the opinion of Shmuel.

The Gemara suggests: Come and hear another proof that a claim for a coin is referring to its value: It is taught in a baraita that if the claimant said: I have a coined gold dinar in your possession, and the defendant responded: You have only a silver dinar in my possession, he is liable to take an oath, as the claim and the admission are both referring to a coin. The Gemara infers: The reason this claim is referring specifically to a coin is that the claimant says to him: You owe me a coined gold dinar; but if the claim was for an unspecified gold dinar, i.e., without specifying that it was coined, the claimant is saying to him that he owes him an item with the value of a dinar, not necessarily a coin, in accordance with the opinion of Rav.

Rav Ashi said in response that according to the opinion of Shmuel, this is what the baraita is saying: Anyone who says: A gold dinar, is considered like one who says: A coined gold dinar; i.e., he is referring to the coin and not to its value.

Rabbi Ḥiyya teaches a baraita in support of the opinion of Rav: If the claimant said: I have a sela in your possession, and the defendant responded: You have only a sela minus two silver ma’a in my possession, he is liable to take an oath. If the defendant responded: I owe you only a sela minus one silver ma’a, he is exempt. Clearly, the reason is that he denied less than two ma’a of the claim, in accordance with the opinion of Rav.

§ Rav Naḥman bar Yitzḥak says that Shmuel says: The requirement that the claim be at least the value of two silver ma’a to render the defendant liable to take an oath was taught only with regard to a case where the oath is due to the claim of the creditor and the partial admission of the debtor. But in a case where the defendant’s liability to take an oath is due to the claim of the creditor and the testimony of one witness in support of the claim, even if the claimant claimed from him only one peruta, the defendant is liable to take an oath.

What is the reason for this distinction? As it is written: “One witness shall not rise up against a man for any iniquity, or for any sin” (Deuteronomy 19:15). It is inferred from here that it is for any iniquity or for any sin that he may not rise up, as the testimony of one witness is not enough for this purpose, but he may rise up to render one liable to take an oath. And it is taught in a baraita: In any place where two witnesses render a defendant liable to pay money, the testimony of one witness renders him liable to take an oath. Therefore, since two witnesses render the defendant liable to pay if the claim is worth at least one peruta, so too, one witness renders him liable to take an oath with regard to a claim of this value.

§ And Rav Naḥman says that Shmuel says: If one claimed that another owed him wheat and barley, and the defendant admitted to owing him one of these types, he is liable to take an oath, as he admitted to part of a claim.

Rabbi Yitzḥak said to him: You have spoken well, and so also said Rabbi Yoḥanan. The Gemara asks: By inference, does this mean that Reish Lakish disagrees with Rabbi Yoḥanan with regard to this matter, since Rabbi Yitzḥak mentioned that Rabbi Yoḥanan agreed, and did not reference Reish Lakish, who often engages in disputes with Rabbi Yoḥanan? The Gemara answers: There is no record of Reish Lakish expressing his opinion at that time. There are those who say that this is because he was tarrying and remaining silent, waiting for Rabbi Yoḥanan to finish his statement, and Rabbi Yitzḥak did not find out whether or not he subsequently disagreed with him, and there are those who say that Reish Lakish was drinking at the time, and he therefore remained silent and did not respond to Rabbi Yoḥanan’s statement.

Let us say that the wording of the mishna supports Shmuel’s opinion: If one claimed that another owes him wheat, and the defendant admitted to owing him barley, he is exempt; and Rabban Gamliel deems him liable to take an oath. The Gemara infers: The reason he is exempt according to the first tanna is that he claimed that he owes him wheat and the defendant admitted to owing him barley; but if the claim was for both wheat and barley, and the defendant admitted to owing him one of them, it can be inferred he is liable to take an oath.

The Gemara rejects this proof: No, it is possible that the same is true, i.e., that even if the claim was for both wheat and barley the defendant is exempt. And the fact that the mishna states that the first tanna and Rabban Gamliel disagree with regard to a case where the claim was specifically for wheat and the defendant admitted to owing him barley is in order to convey to you the far-reaching nature of the opinion of Rabban Gamliel, that the defendant is liable to take an oath even if his admission is not at all of the same type as the claim.

The Gemara suggests: Come and hear another proof from the mishna: If one claimed that another owes him vessels and land, and the defendant admitted to owing him vessels but denied the claim of land, or conversely, if he admitted to owing him land but denied the claim of vessels, he is exempt from taking an oath.