Shevuos, Chapter 6, Mishnah 1. Until now the tractate has dealt with oaths that a person takes upon himself or that his fellow imposes upon him. From here onward the Mishnah and Gemara will deal with oaths that beis din imposes upon a person on the basis of various circumstances. This chapter deals mainly with oaths that are required by Torah law, while the next chapter will deal with oaths that beis din imposes by rabbinic enactment. Our Mishnah deals with the obligation to swear in the case of one who admits to part of a claim (modeh bemiktzas).
What is modeh bemiktzas:
When a person makes a claim against his fellow, and the defendant responds that the debt is not as large as claimed - the plaintiff claims that he is owed one hundred, and the defendant admits to only fifty - this is 'modeh bemiktzas': he admits to part of the claim but not to all of it. In such a case the Torah rules that he must swear in order to uphold his statement that he owes only fifty of the hundred. Our Mishnah comes to establish the minimum sums for which this oath is imposed.
Let us turn to the language of the Mishnah:
"Shevuos hadayanin" - the oaths administered by the judges, which beis din imposes upon a person.
"HaTa'anah shtei kesef" - the claim must be for at least two coins called ma'ah, which is the smallest silver coin. This is derived from the verse in which the matter of modeh bemiktzas is discussed: "If a man gives his fellow money or vessels" - "money" is understood as silver coinage, and the smallest of these coins is a ma'ah. And since it is juxtaposed to vessels, which are stated in the plural, implying two items, money too is stated in the plural - and therefore two silver ma'ah is the smallest sum for a claim.
"VehaHoda'ah beshaveh perutah" - the admission must be for at least the value of a perutah, which is the smallest copper coin. A perutah is one thirty-second of a ma'ah.
Rav and Shmuel disagree about the meaning of "HaTa'anah shtei kesef":
The entire claim amounts to two silver ma'ah, and the admission is not included in this calculation.
The denial is two kesef - the sum that the defendant denies amounts to two ma'ah, while the total claim is larger: two kesef and the value of a perutah, since the admission of a perutah's worth is in addition to the two kesef.
We will explain the Mishnah according to the opinion of Rav, who understands that the denial is two kesef, and the total claim is two kesef and the value of a perutah.
"Ve'im ein hahoda'ah mimin hata'anah - patur":
The Mishnah adds a further condition for the obligation to swear: the admission must be of the same type of item as that which was claimed. For example, if the plaintiff claims "I have a hundred barrels of wine in your possession," and the defendant responds "I admit that I owe you, but fifty barrels of beer" - this is not an admission of the same type as the claim, and it is not considered modeh bemiktzas.
"Keitzad?" - the practical examples in the Mishnah:
The claim is for two kesef only, and no more, and the defendant responds that he owes only a perutah - exempt. For according to Rav, the claim must be for two kesef and the value of a perutah together, so that the denial should amount to a full two kesef, and here the denial is not two kesef.
And the reverse: the claim is for two kesef and a perutah, and the defendant responds that he owes only a perutah, so that his denial amounts to two kesef - obligated, since according to Rav the denial amounts to a full two kesef.
Complete denial: the plaintiff claims "I have a maneh in your possession," and the defendant responds "I have nothing of yours" - exempt, for there is no modeh bemiktzas here. Admittedly we find throughout the Gemara that even in circumstances of complete denial there is an obligation to swear, namely the oath of heses, but that was instituted only after the time of the Mishnah, in the era of the Gemara.
Straightforward modeh bemiktzas: the plaintiff claims "I have a maneh in your possession," and the defendant responds "I have only fifty dinar of yours," which is half a maneh - obligated, by the law of modeh bemiktzas.
But if he claimed "my father had a maneh in your possession," and the defendant responds "your father had only fifty dinar with me" - he is exempt from the oath of modeh bemiktzas, even though he admitted that he owed his father fifty.
"Mipnei she'hu k'meshiv aveidah": - because he is like someone returning a lost object.
The reason for the exemption is that the defendant is comparable to someone who returns a lost object. The claimant, who says that his father had fifty in the defendant's hands, is making an uncertain claim, since he does not know this for a fact - and that is how the Gemara understands his claim. Since the claim is only an uncertain one, and the defendant volunteers on his own that he does indeed owe, though not the entire sum, we do not impose an oath on him. After all, in his honesty he did the claimant a favor by admitting, and he is like someone who returns a lost object that he was under no obligation to return, since in any case there was nothing here but an uncertain claim. We therefore have no wish to impose an oath on him under these circumstances.
In summary: In this Mishnah we learned the parameters of the oath of one who admits to part of a claim, which beis din imposes by Torah law: the claim must be for two silver ma'ah and the admission for the value of a perutah, according to Rav's understanding that the denial itself must amount to two silver ma'ah; the condition that the admission be of the same type as the claim; and the practical examples - the exemption in a case of total denial, the obligation where one admits to part, and the exemption in a case of an uncertain claim because the defendant is like someone returning a lost object.