Bava Batra 171B

לא נחלקו אלא בשטר מאוחר בעלמא –

The two rabbis disagree only with regard to a case of a postdated promissory note in general, i.e., one in which the fact that it is postdated is not readily discernible from the dating of the document, as opposed to one dated on Shabbat or Yom Kippur.

דרבי יהודה לטעמיה, דאמר: אין כותבין שובר, ולא נפיק מיניה חורבא;

As R' Yehuda conforms to his line of reasoning, as he says: One does not write a receipt for a debtor when he pays his debt; rather, the original document is torn, and in the case of partial repayment a new document is written, attesting to the balance due. And consequently, no harm can emerge from a postdated document. There is no concern that the date on the postdated document may have been recorded after the writing of a receipt.

ורבי יוסי לטעמיה, דאמר: כותבין שובר, ונפיק מיניה חורבא.

And R' Yosei conforms to his line of reasoning, as he says: One writes a receipt for a debtor when he pays his debt, in lieu of tearing the promissory note. And consequently, harm can emerge from a postdated promissory note. Harm can occur in a case such as the following: The loan was given on the 1st of Nisan. The debt was paid on the following day and, rather than tearing the promissory note, a receipt was written and dated on the second of Nisan. If the original note had been postdated to the third of Nisan or after that, the creditor could use it to collect his debt a second time, arguing that the debtor’s receipt is irrelevant, as its date is prior to the date in the promissory note.