Observation: This is difficult for Rashi's Perush in Rosh Hashanah (2a). The Mishnah says that the first of Nisan is Rosh Hashanah for kings. The Gemara explains that this affects predated loan documents.

Explanation #1 (Rashi): If they did not fix a day for the beginning of the year of the king, rather, it varies with each king (the anniversary of the day he took reign starts the next year), sometimes one could not tell (which year it was written in);

E.g. if he wrote Kislev in the third year of the king, and witnesses came and said "when we signed it, we did not see that he lent to him. Rather, the borrower told us to sign." This is like we learned, that we write a document for the borrower, even if the lender is not with him;

However, [if they said] "we saw that he gave that loan in Tamuz in the third year of the king, and we do not know if it was before this or after this, for we do not know when the king took reign";

If it was between Tamuz and the following Kislev, and Kislev [of the third year] came first (before the loan in Tamuz of the third year). If so, it is predated, and Pasul;

Or, if [he took reign] between Kislev and the following Tamuz, and it is postdated, and Kosher.

Now that they fixed Nisan to be Rosh Hashanah, [we know that] Tamuz [of the third year] came first (before Kislev of the third year), and it is postdated, and Kosher.

Question #1 (against Rashi): Now, according to Abaye, such a case (the former) is not predated, for witnesses acquire [for the recipient] through their signatures!

Question #2: Also according to Rav Asi, who does not hold [that witnesses acquire for him through their signatures], why did they need to enact, since he holds that we write a document for the borrower [when the lender is not there] only for a Shtar Hakna'ah?

Question #3: Also, is it common that the entire world, including the scribe and Beis Din, will forget when the king took reign, that they needed to enact due to this?

Question #4: Also, [the Gemara] should have said a greater practical difference regarding all documents, that we do not know when to collect them, since we do not know when begins the year of the king!

There are more difficulties [with Rashi's Perush], but this is not the place.

Explanation #2: [Fixing a new year] affects predated documents, e.g. if the king took reign on the 29th of Adar. When the 29th of Adar comes next year, sometimes the scribe errs by one day, and thinks that the king took reign on Nisan 1;

Note: This concern applies no matter which day he took reign. Perhaps Tosfos mentioned Adar 29 to teach that the enactment surely helps even then, for scribes know to start writing "the second year" the next day, like Tosfos proceeds to explain.

He writes now on the 29th of Adar in the first year, and it turns out that this document is predated an entire year. This is Pasul according to everyone, for now he writes the previous year;

However, when they fixed Nisan to be the new year, he will not err. From the second day from when he took reign, i.e. Rosh Chodesh Nisan, the scribe wrote "the second year [of the king]", and from then and onwards until the coming Nisan.

Question: [Rav Asi's answer, that even though one may not write a regular loan document iabo the lender, regarding a found document, we are concerned for this, was difficult] to Abaye. This is astounding. For this (to explain why our Mishnah says that we do not return a document with Acharayus), there was no need to say Edav b'Chasumav Zachin Lo!

Even if he held that witnesses do not acquire for him through their signatures, like Rav Asi, and the Mishnah that says that we write a document for the borrower [when the lender is not there] refers to Shetarei Hakna'ah, and we are not concerned lest one [improperly] wrote [in the absence of the lender]...

He could establish our Mishnah when the borrower admits. He does not return it, because we are concerned for payment and scheming, like it says below!

Answer: "Because it was difficult for Abaye", he was not pleased with Rav Asi's answer. This is an independent matter. It does not refer to Abaye's teaching that witnesses acquire for him through their signatures. (Pnei Yehoshua - Abaye does not come to explain our Mishnah, rather, the Mishnah "we write for the borrower..." He himself held that it is logical that Edav b'Chasumav Zachin Lo, but if so, our Mishnah must be concerned for payment and scheming. It connotes unlike this. However, he did not accept Rav Asi's answer for our Mishnah. Rather, we must say that we are concerned for payment and scheming, so we can say Edav b'Chasumav Zachin Lo.)

Explanation: Rabanan hold that Acharayos Ta'us Sofer (if a document does not mention Acharayos, there is Acharayos. We assume that the Sofer forgot to write it). Therefore, he does not return it, even if there is no Acharayus in it. Also Rav Asi holds like this.

Question: Why do we say that we are concerned for scheming? We should say that we are concerned lest he paid him, and the [document's] Shibud (ability to obligate the borrower) was already pardoned;

Now he wants to borrow with the document again, to save the scribe's fee [for a new document]. Also the lender wants to do so, to be able to collect Meshubadim from the earlier date!

Answer #1: [The borrower] would not cause a big [fraudulent] loss to buyers in order to save the scribe's fee.

Implied question: Rav Asi is concerned lest he wrote in order to borrow, and he never borrowed, and now he wants to borrow, and he will cause a loss to buyers, in order to save the scribe's fee!

Answer: That is because he already paid the scribe, and he does not want to lose [what he paid for the document, and never use it]. Also, the lender reasons that there was publicity from when they wrote the document [so buyers should have known to be careful];

However, when he borrowed and paid, he did not lose the coin he gave to the scribe.

Answer #2: The lender fears that people heard about the payment, and the document was not written for the second loan. (He will not risk not collecting at all, in order to have greater rights of collecting Meshubadim.)

Inference: The borrower claims that it is forged.

Suggestion: Perhaps "nothing ever happened" means "I paid"!

Rejection #1: If so, we should return it to the borrower to wrap on his bottle! (The borrower paid for the document.)

Rejection #2: Shmuel is not concerned for payment.

Question: Even if there is Acharayus, why don't we return it? If he will not be Mekayem it, he will not collect at all. If he will be Mekayem it, he properly collects!

Suggestion: We are concerned lest he present the document not in front of the borrower, or against buyers and orphans, and we will not claim for them Mezuyaf (perhaps it is forged), for this is not common.

This is like we do not claim for orphans that Ones occurred, because it is not common, like it says in Bava Basra (70b);

Since we do not claim for them Mezuyaf, also we do not claim that it was paid.

Implied question: Shmuel holds in Bava Basra (154b) that one who admits that he wrote (authorized) a document, the bearer must validate it. [If not,] he is believed to say that he paid, Migo that if he wanted, he could have said Mezuyaf!

Answer: Even so, for orphans and buyers, for whom we do not claim Mezuyaf, we do not claim that it was paid.

Rejection #1: This is wrong. Even if we do not claim for them Mezuyaf, we claim for them that it was paid, like it says in Bava Basra (70b) regarding Shtar Kis (a document of a business deal. It is half an investment, and half a loan) brought against orphans;

[The bearer] swears and collects half. Regarding the half that is a deposit, we claim for them "I returned it", just like their father would have been believed to say "I returned it", Migo that if he wanted, he could have said that Ones occurred.

Therefore, also for them we claim "I returned", even though we do not claim for them that Ones occurred.

Rejection #2: You are forced to say that we claim for them Mezuyaf, or that it was paid;

If not, no one can survive, for anyone can bring a loan or sale document [forged to say] like he wants, against orphans or buyers, or not in front of him (the borrower) and we will not claim for them!

Support: Bava Basra (174b) proves this. Rav and Shmuel both say that if a Shechiv Mera (dangerously sick person) said "I have 100 Zuz of Ploni", if he said "give [it to him]", we give. If he did not say "give", we do not give;

It explains there that he has a document. If he said "give", he validated the document. If he did not say "give", he did not validate the document.

Inference: We claim Mezuyaf for orphans, for Rav holds in Kesuvos (19a) that one who admits that he wrote a document, the bearer need not validate it. We do not claim [for him] "I paid you";

If so, if he (the Shechiv Mera) did not validate his document, we claim [for his heirs] Mezuyaf!

Reiteration of Question (e): If so, why don't we return [a document with Acharayus]?

Suggestion: Since it fell, it is tainted. Therefore, even if he is Mekayem it, we are concerned lest it was forged.

Therefore, he says not to return it, lest he take [from buyers] when it will be forgotten that it fell.

Rejection #1: We say below (16b) that Shmuel said that if one found a Shtar Hakna'ah, he returns it. If he wrote it to borrow and did not borrow (the borrower already obligated himself)!

Inference: The borrower is not in front of us admitting [that the document is valid], for it says "perhaps he wrote to borrow, and did not borrow." Why should we return it? We should be concerned lest it is Mezuyaf, and even if he is Mekayem it, it does not help!

Rejection #2: Similarly, Rav Asi who said below (17a) if one was Motzi a document with a Henpek, he returns it. Why does he return it? We should be concerned lest he forged the signatures of the judges!

Answer: Shmuel and Rav Asi discuss when the borrower is not in front of us. Therefore, we return it. He need not be concerned lest it is Mezuyaf. When he wants to collect, we will claim Mezuyaf. If he will be Mekayem it, he will collect;

And even if the borrower will come later and claim that it is Mezuyaf, we are not concerned, since [the document] came to his (the lender's) hand in a permitted way.

Support: Below (7b), it says "if someone else found a document that fell to the hand of a judge..."

Inference: If the lender found it, he collects, since it came to his hand in a permitted way.

Distinction: However, here in our Mishnah we discuss that the borrower is in front of us when it is found, and he claims Mezuyaf. Therefore, since it was tainted through falling, and also the borrower claims Vadai Mezuyaf, we do not return it;

We should be concerned lest he collect from orphans or buyers or not in front of the borrower through Kiyum of the document, and Kiyum does not help, for perhaps he toiled to forge the document so well that the witnesses think that it is their signatures;

We find like this in Bava Basra (167a. An expert forged the signatures of Rava and Rav Acha bar Ada. He put his hand on a flask, so it would wobble, while forging the signature of Rav Acha, whose hand shakes.) Rava himself mistook the forgery of his name for his own signature.

Distinction: Perhaps from the borrower himself he can collect through Kiyum. Since [the borrower] himself knows that it is forged, he will toil to refute the proof.

Question: Above (7b), R. Yosi said that if it fell to the hand of a judge, it has its Chazakah, and we are not concerned for payment;

This connotes that the borrower is in front of us, and claims "I paid", like the Reisha, in which two hold the document;

Why isn't he believed to say "I paid", through a Migo that if he wanted, he could have said "it is Mezuyaf"? Then, we would not return it, lest he collect from orphans and buyers, and even if it is Mekuyam, it does not help, like I explained!

Answer #1: This is not a Migo, for it is better for him to say "I paid", so no one can contradict him, than to say Mezuyaf, for he fears lest they validate it;

Even though the Kiyum does not help to collect through it, [the borrower] does not willingly claim something that can be refuted.

Answer #2: If we would say that he can collect from the borrower himself through Kiyum, we could say that "it has its Chazakah" does not mean that we return it to the lender, for there is concern lest he bring it against orphans or buyers...

Rather, if the lender is Mekayem it while the finder holds it, he collects from the borrower, and we are not concerned for payment.

Explanation #1: He (R. Elazar) is not concerned lest he wrote to borrow in Nisan [and did not borrow until Tishrei], like Abaye [who say that witnesses acquire for him through their signatures];

He mentioned scheming due to when it has Acharayus. When it has no Acharayus, scheming does not apply, for he does not collect from Meshubadim. He did not know the Beraisa below [which says that even without Acharayus, he collects from Meshubadim].

Explanation #2: Alternatively, R. Elazar held that when there is no Acharayus (scheming applies, for), he collects from Meshubadim according to Rabanan, for Acharayos Ta'us Sofer Hu.

Implied question: He did not know the Beraisa below [which teaches that Acharayus Ta'us Sofer Hu]!

Answer: He held that if it were not Ta'us Sofer, he would not collect even from Bnei Chorin. Since he pardoned the Shibud, he pardoned also the principal, like R. Meir holds.

Support: It connotes a little like this, since it says "the argument is when the Chayav (the one whom the document obligates) does not admit", i.e. when there is no Acharayus, and regarding this it says afterwards "but if the Chayav admits, we are not concerned for payment and scheming";

Inference: This refers to when there is no Acharayus.

Implied question: We could have brought this without an inference. It explicitly teaches "he collects from Bnei Chorin property"! (Chachmas Mano'ach - Had the Reisha taught "when there is Acharayus, he collects from Meshubadim and Bnei Chorin" we would infer that without Acharayus, he does not collect at all. Rather, the Reisha taught only that with Acharayus, he collects from Meshubadim. We infer that without Acharayus, he does not collect from Meshubadim, but he collects from Bnei Chorin.)

Answer: This is the style of the Gemara [to infer from the Reisha what is taught explicitly in the Seifa].

Implied question: We could say that the reason we do not return is lest he wrote to borrow in Nisan [and did not borrow until Tishrei]!

Answer: In any case it is difficult for R. Elazar, who says that we return, and he is not concerned.

Question: Why is this one matter? R. Elazar did not need to say "when the Chayav admits, all agree that he returns, for we are not concerned for payment and scheming";

He could have said "whether or not he admits, according to R. Meir he returns if there is no Acharayus for he cannot collect anything. According to Rabanan he does not return, for he collects from Meshubadim, and we are concerned for scheming"!

Answer: He said "we are not concerned for payment and scheming" [because] the Mishnah was difficult for him;

It says that he returns all actions of Beis Din. This implies that we are not concerned for scheming. He does not establish it to discuss Chaltasa documents, like [R. Zeira] rejects below;

Since he said so based on our Mishnah, this is not counted [like a second teaching of his].

Distinction: However, his explanation that according to R. Meir, he does not collect anything when there is no Acharayus, the Mishnah did not force him to explain so. Therefore, we say that one [teaching of his was refuted].

Explanation: Shmuel was contradicted about two laws, for his teaching that we are not concerned for payment and scheming, is not due to our Mishnah, for he said in general that if one found a Shtar Hakna'ah in the market [he returns it].