Bava Metzia 13B

דאמר לא היו דברים מעולם.

the one who says that these matters, the loan, never happened and that the promissory note is forged. Therefore, he has no claim to the paper on which the promissory note is written.

אמר רבי אלעזר: מחלוקת בשאין חייב מודה. דרבי מאיר סבר: שטר שאין בו אחריות נכסים ⁠– אינו גובה לא ממשעבדי ולא מבני חרי. ורבנן סברי: ממשעבדי הוא דלא גבי, מבני חרי ⁠– מגבא גבי. אבל כשחייב מודה ⁠– דברי הכל יחזיר, ולא חיישינן לפרעון ולקנוניא.

§ R' Elazar says: The dispute in the Mishnah between R' Meir and the Rabbis is in a case when the purported liable party does not admit to the debt. As, R' Meir holds that with a promissory note that does not include a property guarantee, one can collect a debt neither from liened property that has been sold nor from unsold property. And the Rabbis hold that it is only from liened property that one cannot collect a debt using this promissory note but that one does collect a debt from unsold property. But in a case when the liable party admits to the debt, everyone agrees that the finder must return the promissory note, and we do not suspect the creditor and the debtor of engaging in repayment and collusion [veliknuneya] to the detriment of one who purchased land from the debtor.

ורבי יוחנן אמר: מחלוקת כשחייב מודה, דרבי מאיר סבר: שטר שאין בו אחריות נכסים ⁠– ממשעבדי הוא דלא גבי, אבל מבני חרי ⁠– מגבא גבי. ורבנן סברי: ממשעבדי נמי גבי. אבל כשאין חייב מודה ⁠– דברי הכל לא יחזיר, דחיישינן לפרעון.

And R' Yoḥanan says: The dispute is in a case when the liable party admits to the debt. As, R' Meir holds that it is only from liened property that one cannot collect a debt using a promissory note that does not include a property guarantee, but one does collect a debt from unsold property. And the Rabbis hold that one collects a debt from liened property too. But in a case when the liable party does not admit to the debt, everyone agrees that the finder may not return the promissory note, as we suspect that perhaps there was repayment.