The two Sages 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.

As Rabbi 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.

And Rabbi 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 first 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 thereafter, 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.

§ Rav Huna, son of Rav Yehoshua, says: Even according to the one who says that one writes a receipt for the debtor when he pays, in lieu of tearing the promissory note, this statement applies only with regard to a case where the debtor pays half, i.e., a portion, of the debt. But with regard to a case where the debtor comes to repay all of the debt and the creditor has lost the promissory note and cannot tear it, all agree that one does not write a receipt. Rather, the debtor will not be required to repay the loan unless the creditor can produce the promissory note.

The Gemara rejects this opinion: But it is not so; we write a receipt even in a case where the debtor pays all of the debt.

The Gemara proves its assertion: This is like that case where Rav Yitzḥak bar Yosef was owed money by Rabbi Abba. Rav Yitzḥak bar Yosef came before Rabbi Ḥanina bar Pappi, and said to Rabbi Abba: Give me my money. Rabbi Abba said to him: First give me my promissory note, and then take your money. Rav Yitzḥak bar Yosef said to him: I lost your promissory note; instead, I will write a receipt for you. Rabbi Abba said to him: Isn’t there the opinion of Rav and Shmuel, who both say that the halakha is that one does not write a receipt?

Rabbi Ḥanina bar Pappi, the judge, thereupon said: Who will give us some of the dust of Rav and Shmuel, and I will place it on my eyes, so highly do I regard them. Nevertheless, isn’t there the opinion of Rabbi Yoḥanan and Reish Lakish, who both say that one writes a receipt?

And similarly, when Ravin came from Eretz Yisrael to Babylonia, he said that Rabbi Ilai says: The halakha is that one writes a receipt.

The Gemara concludes: And it stands to reason that one writes a receipt. As, if it would enter your mind that one does not write a receipt, then if the promissory note of this creditor is lost, should this debtor eat and rejoice? Is it fair that he should keep money that he knows he owes the creditor?

Abaye objects to this line of reasoning: Rather, what should the halakha be, that one writes a receipt when the creditor cannot find the promissory note? If the receipt of the debtor is lost, should this creditor eat and rejoice? Once the debtor has lost his receipt, there is nothing to prevent the creditor from collecting the debt a second time. This, too, is unfair. In either case, whether a receipt is written or not, an injustice could result. Why should it be preferred that the potential of suffering an injustice should be borne by the debtor rather than the creditor? Rava said to Abaye: Yes, it is preferable, because, as it is written: “The borrower is a servant to the lender” (Proverbs 22:7). The debtor’s interests are subordinated to those of the creditor.

§ We learned in a mishna elsewhere (Shevi’it 10:5): Promissory notes that are antedated are not valid, but those that are postdated are valid.

Rav Hamnuna says: They taught this halakha only with regard to promissory notes, but with regard to deeds of buying and selling property, even postdated documents are not valid. What is the reason for this stringency in the case of bills of sale? If postdated documents were allowed, there could be times that the seller sells land to the purchaser in the month of Nisan of a particular year and writes a postdated deed for him stating that the sale took place in the following Tishrei, and some money happens to reach the seller between Nisan and Tishrei and he purchases the land back from the purchaser. And then, when Tishrei arrives, the purchaser takes out the original bill of sale and says to the seller: It is true that you purchased the field from me, but I then purchased it from you again now, in Tishrei, as stated in this document.

The Gemara asks: If so, a similar scenario could occur with promissory notes as well: There could be times that one borrows money in Nisan and writes a promissory note for the creditor stating that the loan took place in the following Tishrei, and some money happens to reach the debtor between Nisan and Tishrei and he repays his debt to the creditor early and says to him: Give me my promissory note. And the creditor says to him: I lost it, and he writes him a receipt instead. And then, when the time written in the note arrives, the creditor takes out the supposedly lost promissory note and says to the debtor: It is true that you repaid me previously, but it is now, after you repaid that loan, that you borrowed from me these dinars recorded in this document, which is dated in Tishrei.

The Gemara answers: Rav Hamnuna holds that one does not write a receipt, so that scenario cannot occur. Like Rabbi Yehuda, Rav Hamnuna maintains that if a creditor loses his promissory note the debtor does not have to repay the loan. Rabbi Yosei, who does allow the creditor to collect his debt in such a case and write a receipt for the debtor, is concerned about that scenario, and consequently he holds that postdated promissory notes are not valid.

Rav Yeimar said to Rav Kahana, and some say it was Rav Yirmeya of Difti who said this to Rav Kahana: And today, when we write postdated promissory notes, and we also write a receipt in cases where the creditor loses his promissory note, why do we do this? The combination of allowing postdated promissory notes and allowing the writing of a receipt instead of producing the promissory note would enable double collection of the loan to take place. Rav Kahana said to him: The problem was rectified after Rabbi Abba told his court scribe: When you write postdated promissory notes, write as follows: We did not write this document on its date, i.e., on the date written within the document; rather, we postdated it and wrote it. Since it is clear from the text of the document that it was postdated, double collection of the loan is avoided.

Rav Ashi said to Rav Kahana: But what about today, when we do not do this, i.e., we do not follow Rabbi Abba’s instructions? How do we avoid double collection of the loan? Rav Kahana replied: The problem was rectified after Rav Safra said to his court scribe: When you write these receipts for debtors who pay debts without the original promissory note being torn, if you know the date written in the missing promissory note, write it into the receipt. But if you do not know the date written in the promissory note, write the receipt without specification, i.e., do not write any date at all in the receipt, so that whenever the creditor produces the promissory note, the undated receipt can weaken it, i.e., exempt the debtor from payment.

Ravina said to Rav Ashi, and some say it was Rav Ashi who said to Rav Kahana: