- Claiming payment for a שטר was סיטראי – a side debt
A lender once demanded payment of a hundred-zuz loan, which the borrower claimed he paid, but the lender replied "הנהו סיטראי נינהו" – “Those monies were for a side (different) debt. Rav Nachman said: איתרע שטרא – the document is weakened, since the lender agreed he received payment, and he cannot collect with the שטר. Rav Pappa said the שטר is not weakened, and the Gemara asks why this is different from an incident in which the borrower claimed to have repaid a loan, saying the money was given to him to purchase oxen (and they would divide the profits), and the lender was present at the sale of their meat. Here, too, the lender claimed the payments were for סיטראי – a side debt, yet Rav Pappa said the שטר is weakened!? The Gemara answers that since this money was given for purchasing oxen, and he collected payment from them, this indicates the payment was for this debt.
The halachah is that the שטר is weakened in such cases, but only if עדים witnessed the payment and the borrower did not mention the שטר; otherwise, the lender has a מגו that he could have denied the payment.
- Swearing מודה במקצת to a קטן who was בא בטענת אביו
The Mishnah taught that one does not swear against the claim of a קטן, but then states that one does swear to a קטן. Rav explains that this case is בבא בטענת אביו – when he comes with his father’s claim, following Rebbe Elazar ben Yaakov, who ruled that if one says, “A maneh of your father’s was in my possession, and I repaid half of it,” he must swear. The Chachomim say: אינו אלא כמשיב אבידה ופטור – He is like one who returns lost property and is exempt from swearing. The machlokes is ultimately explained based on Rabbah’s rationale for the shevuah of מודה במקצת. He explains that the נתבע does not avoid swearing based on his ability to have fully denied the debt, because חזקה אין אדם מעיז פניו בפני בעל חובו – it is presumed that a person is not brazen enough to completely deny his debt to his creditor’s face. Rebbe Elazar ben Yaakov holds he cannot even completely deny the claim to the creditor’s son, and therefore must swear. The Chachomim hold one would be brazen enough to fully deny the claim to his son. Since he partially admitted voluntarily, he is exempt from swearing, like one who returns a lost item.
- אלו דברים שאין נשבעין עליהן (land, etc.)
The next Mishnah states: ואלו דברים שאין נשבעין עליהן – and these are the things about which one does not swear: העבדים והשטרות והקרקעות וההקדשות – slaves, documents (of debts), land, and hekdesh. Additionally, a thief does not pay double for stealing them, and one would not pay four or five times the value after stealing and shechting (or stealing) an animal of hekdesh. A שומר חנם – unpaid watchman does not swear about these items (that their loss was not due to his negligence), and a שומר שכר – paid watchman does not pay if they are lost or stolen. Rebbe Shimon says that one does swear about קדשים שחייב באחריותן – hekdesh which the owner is responsible to replace if it is lost, because it is considered to be his personal property.
Rebbe Meir and the Chochomim disagree if one must swear about grape-laden vines, and the Gemara will explain that they are discussing grapes which are עומדות ליבצר – ready to be harvested, and argue if they are considered already harvested (and מטלטלין).