אָמַר אֶלָּא לְבָרֵר אֲמַר לֵיהּ אֲנָא נָמֵי לְבָרֵר קָאָמֵינָא: say that the litigant loses the case if he cannot produce verification of his extraneous claims, but only that he is told to verify those claims if he can. Rabbi Yitzḥak Nappaḥa said to Rabbi Abba: I, too, am saying only that you are required to verify your claim if you can; if you cannot, you will not be required to pay.
מַתְנִי׳ מִי שֶׁפָּרַע מִקְצָת חוֹבוֹ רַבִּי יְהוּדָה אוֹמֵר יַחְלִיף רַבִּי יוֹסֵי אוֹמֵר יִכְתּוֹב שׁוֹבָר אָמַר רַבִּי יְהוּדָה נִמְצָא זֶה צָרִיךְ לִהְיוֹת שׁוֹמֵר שׁוֹבָרוֹ מִן הָעַכְבָּרִים אָמַר לוֹ רַבִּי יוֹסֵי כָּךְ יָפֶה לוֹ וְלֹא יֵרַע כֹּחוֹ שֶׁל זֶה: MISHNA: In the case of a debtor who repaid part of his debt, Rabbi Yehuda says: The creditor should exchange the promissory note for a new one stating the current balance and tear up the first promissory note. Rabbi Yosei says: The creditor may keep the original promissory note, and he should write a receipt for the payment he has received and give it to the debtor as proof of his partial payment of the sum recorded in the old note. Rabbi Yehuda said with regard to this arrangement: It is found that this debtor must now guard his receipt against being destroyed by mice, as if he no longer has the receipt, he will have to pay the entire sum recorded in the promissory note. Rabbi Yosei said to him: This situation is fitting for him; it is better that this procedure be followed, and the strength of the claim of this creditor not be weakened.
גְּמָ׳ אָמַר רַב הוּנָא אָמַר רַב אֵין הֲלָכָה לֹא כְּרַבִּי יְהוּדָה וְלֹא כְּרַבִּי יוֹסֵי אֶלָּא בֵּית דִּין מְקָרְעִין הַשְּׁטָר וְכוֹתְבִין לוֹ שְׁטָר אַחֵר מִזְּמַן רִאשׁוֹן GEMARA: Rav Huna says that Rav says: The halakha is not in accordance with the opinion of Rabbi Yehuda, nor is it in accordance with the opinion of Rabbi Yosei. Rather, the halakha is that the court tears up the original promissory note and writes a different promissory note for the creditor, listing the new sum owed, dated from the time of the first document.
אֲמַר לֵיהּ רַב נַחְמָן לְרַב הוּנָא וְאָמְרִי לַהּ רַב יִרְמְיָה בַּר אַבָּא לְרַב הוּנָא אִי שְׁמִיעָא לֵיהּ לְרַב הָא [בָּרַיְיתָא] דְּתַנְיָא עֵדִים מְקָרְעִין אֶת הַשְּׁטָר וְכוֹתְבִין לוֹ שְׁטָר אַחֵר מִזְּמַן רִאשׁוֹן הֲוָה הָדַר בֵּיהּ Rav Naḥman said to Rav Huna, and some say it was Rav Yirmeya bar Abba who said this to Rav Huna: If Rav would have heard this following baraita, as it is taught in a baraita that according to Rabbi Yehuda the proper procedure is that the witnesses tear the original promissory note and write another promissory note for the creditor listing the new sum owed, dated from the time of the first document, he would have retracted his statement that the court tears the promissory note and writes a new one.
אֲמַר לֵיהּ שְׁמִיעַ לֵיהּ וְלָא הֲדַר בֵּיהּ Rav Huna said to him: Rav heard the baraita, and nevertheless he did not retract his statement. While Rabbi Yehuda says in the baraita that the witnesses write a new promissory note, Rav maintains that this must be done specifically by a court. Why is this?