Gemara

168b (Beraisa): If Shimon claims that he lost his loan document, even though witnesses say that they wrote, signed and gave to him the document, we do not write another document for him.

We do write another document of sale, but without Acharayus (liability to compensate the buyer if the land is legally taken from him).

169a - Question: We should write a new sale document with Acharayus, and give Reuven (the seller) a document saying that Shimon can collect Acharayus only with a document with the date of the new document!

Inference (Rabanan): We do not force one to accept a Shover (receipt, or any document that negates a different document) to enable another (who lost his document) to receive what he deserves.

Rejection (Rav Papa or Rav Ashi): Normally we force one to accept a Shover. Here we do not, lest a creditor take Shimon's land, and Shimon will collect (with the original document) from later buyers, who have no Shover.

Question: If so, for the same reason we should not write a Shover for one who lost a loan document!

Answer: When a creditor comes to collect from buyers, since he is owed money, they suspect that the borrower paid, so they will not give up their land before asking the borrower. Here, Shimon's land was taken. He wants back land, so buyers do not think that he accepted money from Reuven in its stead.

Kesuvos 16b (Beraisa): If a woman lost her Kesuvah, and witnesses say that her Nisu'in was like the custom for virgins, she collects 200.

Question: We should be concerned lest she bring witnesses and collect in Beis Din, and show her Kesuvah and collect again in another Beis Din!

Answer (R. Avahu): This shows that we write a receipt.

Question: Perhaps later she will collect again with the Kesuvah!

Answer #1: 'Lost' in the Beraisa means that it was burned.

Question: We should be concerned lest she bring witnesses and collect in Beis Din, and bring witnesses and collect again in another Beis Din!

Answer: Certainly, where there is no alternative, we write a receipt.

Rishonim

Rambam (Hilchos Malveh 23:11): Regarding loan documents, even if the witnesses are around, and they acquired from him, and he said 'the document you wrote for me was lost or burned' we do not write another for him. Perhaps the loan was paid or pardoned, even if it was not due yet. He does not collect with these witnesses unless the borrower says 'I never borrowed', for then he is established to be a denier.

Rebuttal (Ra'avad): Since it is within the time of the loan, he can collect and write a receipt!

Rosh (Teshuvah 94:5): The Beraisa says that if one says that he lost his document, we do not write another for him. The Rashbam derived that if witnesses testify that the first was lost, we write another, without concern lest he find the lost document. This is difficult. A woman who lost her Kesuvah can collect it through witnesses who testify that she married like a virgin. We asked that perhaps she lies or will find it, and answered that she collects only if witnesses say that her Kesuvah was lost, i.e. burned (Kesuvos 16b). We can similarly answer the Rashbam's Diyuk. When he says that it was lost, i.e. burned, we do not write another, but we write if witnesses say so. However, we are concerned lest one find a document that he himself lost, for he knows where it was lost. We are not concerned if witnesses say that someone else lost it.

Rebuttal (Shach CM 41:11): The Sugya in Kesuvos is like the opinion that we do not write a receipt. We hold that we write a receipt. The Rashbam explains this opinion. The Sugya in Kesuvos connotes that according to the opinion that we write a receipt, we are not concerned about (the lender finding) a lost document. The Beis Yosef says that even though we write a receipt, we are concerned lest he find his document, and the borrower will not demand a receipt, for he gets back his document. This is wrong. In Kesuvos R. Avahu inferred that we write a receipt, i.e. and if the husband will show the Kesuvah, she does not collect again. Also here, the borrower can show the document, and the lender will not collect again. (He knows that a copy was written, so he will hold the document like a receipt.)

R. Akiva Eiger: The Rosh (Bava Metzia 1:9) rules that we write a document for a borrower in the absence of the lender. If so, if a borrower holds a loan document, this does not proves that he paid!

Shach (ibid.): The Rambam and Sefer ha'Terumos connote like the Rashbam. Gidulei Terumah asked that there is concern lest it was paid. Even the Ra'avad permits only before the loan was due! This is not difficult. We discuss when witnesses testify that it was lost b'Ones, e.g. Nochrim captured the city. The Rashbam is stringent when he claims that he lost it, but when witnesses say so, we write another, and the borrower takes a Shover when he pays.

Dagul me'Rvavah: We need witnesses, for perhaps the loan was already paid. If the borrower admits that he did not pay, this suffices.

Dagul me'Rvavah: We need witnesses, for perhaps the loan was already paid. If the borrower admits that he did not pay, this suffices.

Gra (41:19): It seems that the Rashbam retracted (168b DH bi'Shtarei - we are concerned lest the lender find the document afterwards). The Maharsha says that the Rashbam is not concerned for this when witnesses say that he lost it.

Poskim

Shulchan Aruch (CM 41:3): If Shimon lost his document and asks Beis Din to write a new document for him, we do not, even though the witnesses of the first document say that they wrote and gave it to him. Beis Din does not make a copy of any document unless they see a need, e.g. a loan document was erased. If they wrote a Tofes (a loan form, and added the details of the loan), Beis Din does not collect for him until he gives the document itself, unless they wrote why they made a copy, e.g. the first document was erased.

Beis Yosef (DH Kosav): The Rashba says that whenever there is a need, we write a Tofes. It says at the top why the Tofes was written, and at the bottom that it is a mere Tofes for a proof, but not to collect. In another Teshuvah he wrote that we do not copy a document (in a way that can be used to collect) even for orphans who are away, lest it be used to collect a second time.

SMA (19): We are concerned lest he collect again with the copy. If the copy would say that it is not for collection, it would not hep at all!

Note: It could refute a borrower who says 'I never borrowed.'

Gra (18): We are not concerned lest Beis Din err, but we are concerned lest they forget. When Beis Din writes a Tirfa (authorizing a creditor to check which land was the borrower's), they must tear up the loan document. A Tirfa is valid only if it says 'the loan document was torn' (169a).

Shulchan Aruch (ibid): We do not write unless witnesses know that the document was lost. Even if they know that it was lost, we do not write, lest he find it, unless they testify that it was burned.

Shach (11): It seems that even the Rosh and Beis Yosef agree that we may write a new document if we inform the borrower. This explains why the Rosh (68:31) says that when we know that it was lost, we write another. (Also, there he discusses when the document was totally lost.) The Poskim do not argue. The Rosh and Beis Yosef discuss when we do not inform the borrower; the Rashbam and Rambam discuss when we inform him.

Tumim (2): Chachamim enacted to accept testimony about a fading or lost document not in front of the borrower, lest it get totally erased or the witnesses leave before the borrower returns. The Shach must agree regarding a lost document. If not, we would not need to inform the borrower! he would always know! st it get (is away

Shach (12): We should be concerned lest he burn the document in front of many pairs of witnesses, and (get multiple copies, and) collect more than once! Since we write a Shover, we are not concerned for this. We must say that the new document is from the current date, lest the lender and borrower scheme, and the borrower will hide his Shover and allow the lender to collect from buyers more than once. This is why the Shulchan Aruch (Sa'if 1) requires tearing the first document, for it is from the initial date. The Ra'avad says that Beis Din writes another document only when the witnesses say that no other witnesses saw the document burn. The Rosh (Bava Basra 3:38), Tur and Shulchan Aruch (116) say similarly (in another case). Perhaps also here they discuss when there were no other witnesses.