Explanation #1 (Rivam): He does not collect from Meshubadim, but he collects from Bnei Chorin based on the document;

The witnesses are not Pesulim, for they are not Edei Chamas, for they do not profit anything from the matter.

Question (Tosefta - 5:23): If one finds a document with Ribis, he tears it. If it came to Beis Din, they tear it.

If he collects from Bnei Chorin based on the document, why do they tear it? They should wait until he collects with it first!

Answer: It is forbidden to delay [keeping] it [lest it be used to collect Ribis].

Explanation #2: It seems that R. Meir totally fines, and one may not collect with it at all, just like predated loan documents. Below, we establish like R. Meir (the Mishnah that disqualifies them).

Question: Also there, Rashi explained that they are Pasul only for collecting from Meshubadim!

Answer: This is wrong. "They are Pesulim" connotes that he does not collect with them at all.

Implied question: It says "granted, he may not collect from the earlier date. He should collect from the latter date!" (According to Tosfos, we should have asked why one may not collect from Bnei Chorin!)

Answer: We could have asked also "granted, he may not collect from Meshubadim. He should collect from Bnei Chorin!" We asked even more, that even from Meshubadim, he should collect from the latter date.

Implied question: Below, regarding the episode of the orchard (Ploni ate the Peros for three years due to a loan, and threatened to claim that he bought it if the owner will not sell it to him. The owner was Makneh it to his son, then sold it to Ploni. Rava said that Ploni cannot use the sale document to get back his money from Meshubadim, for there was no Heter to write it. Ravina) asked that R. Yochanan said that it is a decree [about predated documents, not to collect from the true date of the loan], lest he collect from the date written. [According to Rava] he should say that there was no Heter to write it!

(Tosfos said that one may not collect with a predated document at all.) Why didn't [Mereimar] answer that the reason "there was no Heter to write it" helps only not to collect from Meshubadim [and R. Yochanan said that it is a decree not to collect with it at all]?

Answer: This is because [Mereimar] holds that surely, [the reason that there was no Heter to write it] helps to totally disqualify it, and he does not collect with it at all.

Implied question: [Regarding the orchard,] why is the question only whether he collects from Meshubadim, but it is obvious that he collects from Bnei Chorin, even though there was no Heter to write it?

Answer: There, it is obvious that he collects, because the seller admits to the buyer that he did not pay.

Assertion: It seems that even if there are other witnesses, or the borrower admits, R. Meir fines [that the lender does not collect].

Source #1: It connotes that "he does not collect the principal" is like "[he does not collect the] Ribis" (he does not collect it in any case).

Source #2: Also the Tosefta (5:22) connotes that [R. Meir] fines even for a Milveh Al Peh;

Citation (5:22): If one lent his friend with Ribis and came in front of Beis Din, we fine him. He does not collect the principal, and not the Ribis, for R. Meir used to say that a document with Ribis...

Source #3: Also in Bava Kama (30b) we compare the case of fining the matter itself due to the Shevach. He loses the matter itself. Likewise, [here] he fines the principal of the loan.

Disclaimer: We can reject this! There, the Aveirah was done with the money itself more than here. Here, the primary Aveirah is in the document, like we say there "from the time of the writing he did Suma (imposed Ribis), therefore they fined only with a document";

However, Rabanan hold that surely they did not fine at all.

Inference: It connotes that according to Rabanan, he collects the principal with the document even from Meshubadim, and also R. Meir argues only due to a fine.

Question: Why aren't the witnesses Pasul, since they transgress "Lo Sesimun"?

Even though they do not profit, they should be Pasul, just like a transgressor who eats Neveilos to anger Hash-m. We hold like Abaye, that he is Pasul (Sanhedrin 27a)!

Implied question: Why aren't [the witnesses] listed in Sanhedrin (24b, among those Pasul for testimony)?

Answer: Likewise, it does not count the borrower! Rather, he is included in "a loan that comes with Ribis." Likewise, the witnesses are included.

Suggestion: The case is, Ribis is not explicit in the document. Rather, it says Stam "Ploni owes 100 to Ploni." The principal and Ribis are included [in 100], and the witnesses did not know.

Rejection: If so, when R. Yochanan says below that Rabanan agree about predated loan documents, due to a decree lest he collect from the first date (the date on the document)...

Also here, we should decree lest he collect the Ribis as if it were principal!

Suggestion: Since the Ribis is explicit in the document, the witnesses do not transgress "Lo Sesimun", for the witnesses know that Beis Din will not collect Ribis through them. Therefore, the document is valid;

Implied question: If so, why does the Mishnah (below, 75b) say that the witnesses transgress?

Answer: That is when the Ribis is not evident in the document, and the witnesses know that there is Ribis.

Rejection: Regarding this document itself, it says in Bava Kama (30b) and Bava Basra (94b) that from the time of writing [they transgress, for] he did Suma!

Answer #1: Here we discuss Ribis mid'Rabanan. They are not disqualified for an Isur mid'Rabanan, since they do not profit at all, even though for a Torah Isur they would be disqualified.

Answer #2: Even for Ribis mid'Oraisa, we can be Machshir [the witnesses]. Perhaps people think that "Lo Sesimun" refers to the lender, and not the witnesses, therefore they are Kesherim;

This is like we say above (5b) that people think that "Lo Sachmod" is when he does not pay. (Therefore, one who pays is not disqualified due to it.)

Question: Regarding predated documents, how are the witnesses Kesherim?

We establish it like R. Meir, but according to Rabanan, he collects from the latter date, and also according to R. Meir, he would collect, if he did not fine!

Also R. Yochanan did not say that they are Pesulim according to Rabanan. It is only a decree lest he collect from the first date!

Summation of question: The witnesses intentionally signed on falsity, and predated it! (They should be Pesulim!)

Answer #1: The case is, there are witnesses who testify about them that they were mortally coerced.

Answer #2: The witnesses say "we erred about the year of the king." (They mistakenly thought that his reign began later in the year than the document was written, so they wrote the year of his reign to be one less than the correct number.)

Answer #3: The witnesses erred about which day was declared Rosh Chodesh, and the document did not mention which day of the week, only which day of the month.

Pesak: Even though we say in Kesuvos (60b) that the Halachah follows R. Meir in his decrees, that is only regarding his decrees, but not regarding his fines, and this is a fine.

Support: Similarly, Bahag ruled like Rabanan of R. Meir regarding [marrying] a woman pregnant with or nursing another man's baby. If he married, he must divorce her, and when the time to marry (after 24 months of nursing) comes, he marries her;

This is unlike R. Meir, who says that he may never marry her (Sotah 26a), which is a fine.

Proof: In Yevamos (37a), the Gemara asked if she married a Kohen, whether [Rabanan] were stringent to obligate divorcing her, since he cannot remarry her, since a divorcee is forbidden to a Kohen. (According to R. Meir, there is no question. Even a Yisrael may never remarry her! This shows that the Halachah follows Chachamim.)

Question: How is R. Asi's teaching relevant here?

Answer: Here, he asks whether or not he collects from Meshubadim only because it is obvious to him that he is believed to say "I paid", because the document should not have been written;

He asks if he does not collect from Meshubadim, since the document helps only through his admission. Or, perhaps he collects!

About this, Abaye brought from R. Asi that just like one who admits about a document (that he authorized it), his admission helps to collect from Meshubadim, even though had he said that it is forged, [the lender] would have needed Kiyum. The same applies here, regarding the orchard.

Assertion: It is not appropriate for the text to say here "he need not do Kiyum." Rather, the text says "this is like R. Asi taught, for R. Asi said that if one admits that he authorized a document, [the lender] collects from Meshubadim."

Implied question: When we challenged Rava from the Beraisa of Shevach of land, without Rava we could have asked immediately according to everyone;

Why is here different, that he is believed to say "I paid", and regarding [a field] that was found not to be his (the seller's), he is not believed as long as the sale document is in [the buyer's] hand?

Answer: He waited until the end, and challenges Rava from collecting Meshubadim, which was taught explicitly in the Beraisa.

Explanation: If not that he can borrow, even though he can buy, this would not be considered a price to contract based on it.

Pesak: The conclusion is that one may borrow. According to Bahag, that we discuss Se'ah b'Se'ah, the case is, the borrower has coins, so he could buy in the market;

Or [it suffices that] he has [money to buy] a little [of the species he buys], like R. Yitzchak below (75a), that if he has a Se'ah, he may borrow many Korim based on it.

Question: Why do we need a market price? It should suffice that he finds Peros to buy, even if they are expensive! (Maharsha - according to the Ri, who holds that the borrower need not have money, there must be a market price.)

Alternative text: Some texts say "we do not borrow based on Peros in the market."