Explanation #1 (Rashbam): This is like R. Shimon, who said (Bava Kama 98) that Davar ha'Gorem l'Mamon k'Mamon Dami. If Ploni stole Chametz, and Pesach passed, and Reuven burned it [Reuven is liable. Even though it is Asur b'Hana'ah, it had value for Ploni, for through returning it, he could have exempted himself from paying for it.]

Explanation #2 (Rashbam): It is even like Rabanan. There, surely they hold that it is not like Mamon, for it has no value to anyone, except for the Gazlan, to be exempt through it;

However, here it is as if he stole wheat itself, for he sells pebbles to everyone like [part of] the wheat.

Distinction: This is unlike one who burns another's documents. There, he merely burned paper, and not the debt.

Explanation #1 (Rashbam): He decreases [the amount of other species], and afterwards sows.

Explanation #2: If they were sown and did not take root yet, he decreases.

However, if they took root, there is no solution, for they already took root and became forbidden through taking root.

Objection #1: The expression "he diminishes" connotes that they already took root.

Objection #2: R. Yosi says, he removes all of it, because it looks like he is Mekayem (guards) Kil'ayim. Before they took root, it does not look like he is Mekayem Kil'ayim!

Objection #3: In Mo'ed Katan (6a), we bring this explicitly regarding attached Zera'im.

Explanation #2: Rather, it seems that here we discuss what is attached to the ground.

The Rashbam explained that if they took root, there is no solution. Amidst his sharpness, he did not investigate. It says so in Pesachim (25a) only regarding Kil'ai ha'Kerem;

However, one may eat and benefit from Kil'ai Zera'im, like it connotes in Chulin (115a);

It asks "if so ("Lo Sochal Kol To'evah" forbids eating and benefit from everything the Torah made abominable to us, such as meat and milk, which are forbidden to cook together), Kil'ai Zera'im should be forbidden, for the Torah forbids you [to plant it]!

It answers "just like your animal, what comes from it is permitted, also your field." (The Torah wrote the Isur of Kil'ai Zera'im next to crossbreeding, to equate them.)

Opinion #1: The question was against the version that it is a fine, for it teaches "he diminishes", and we do not fine less than a Rova due to a Rova;

However, according to the version that it is Dina (according to letter of the law), we could not ask, for it is different. There, because it is more than a Rova, he does not pardon, like the Rashbam himself explained that we could have answered so.

Opinion #2: We can resolve that we ask also against the version that it is Dina. Whatever people normally remove, if he did not remove it, it is Kil'ayim;

Since it is the way of people, that when they sift, they sift out everything, also regarding Kil'ayim, it is Kil'ayim until he removes everything.

Disclaimer: In any case, the version of a fine is resolved more.

Implied question: We could have answered that he holds like R. Yosi, who says that he removes all of it!

Answer: We prefer to establish it like everyone.

Assertion: The text does not say "Ta Shma", for according to the rejection (immediately before this) that this is a mere stringency, it is unreasonable that R. Yosi would fine;

[The one who brought the Seifa] holds that it is unreasonable to say that R. Yosi argues and holds that a Rova is not common, and Rabanan hold that it is common, for it is unreasonable that they argue about this.

Implied question: We could have answered that there, surely there is one who is not a swindler. Here, can we say that he is not a swindler? I can say that he [intentionally] mixed in!

Answer: We gave a better answer.

Assertion (Ri): R. Meir totally fines to lose the debt. Even through admission or another testimony [he does not collect].

Source #1: The words "he does not collect the principal" connote that he does not collect at all.

Source #2: It connotes that [principal] is similar to Ribis (he does not collect it in any case).

Source #3: In Bava Kama (30b), regarding one who takes out his straw [to Reshus ha'Rabim], they fined the matter itself due to the Shevach (expected improvements). He loses the Mamon itself.

Implied question: In Bava Metzi'a (72b), we compare a document with Ribis to predated loan documents, and we establish [the Mishnah] of a [predated] loan document like R. Meir;

How do we compare these? Here he loses the loan itself. There, he does not lose the loan itself, just the document is Pasul!

Answer: There, there was no Aveirah in the loan itself, only in the document. Regarding Ribis, there is an Aveirah in the loan, even without the document.

Implied question: It says that from the time of writing [the document] he did Simah (imposed Ribis on him)!

Answer: In any case, also without a document, there is an Isur through the loan.

Question (Rivam): If he totally loses his debt, we find that the borrower is a sinner (he agreed to pay Ribis) who profits!

Answer (Ri): This is not difficult. The lender, who gains [through rented], they fined him to lose the matter itself due to the Shevach. Due to this, he will be careful;

There is no matter in which to fine the borrower so he will be careful. From the beginning, he borrowed with intent to pay!

Question #1 (Rashba): Why didn't he bring [the Mishnah] of predated loan documents?

There, they totally fined [not to collect Meshubadim] from the first date [on the document], and [not] from the second date (when he truly borrowed), even though also there, we can say "who says that he will collect from Meshubadim? Perhaps he will never come to collect from Meshubadim!"

Question #2: We can ask similarly in the Sugya in Bava Kama (30b. Rav says that they fined one who takes out his straw to Reshus ha'Rabim to lose even the matter itself. R. Ze'iri says that they did not, for perhaps it will not damage anyone.)

Answer (Ri): Just like here, from the time of writing he did Suma, also there (a predated document), from the time of writing he transgress "mi'Devar Sheker Tirchak."

Inference: He collects with the document, even from Meshubadim.

Question (Ri): Why is the document Kosher? The witnesses transgressed "Lo Sesimun", like the Mishnah in Bava Metzi'a (75b) says!

Implied question: (Why should they be disqualified?) They are not 'Edei Chamas', since they do not gain anything [through their testimony]!

Answer: We hold like Abaye, that a transgressor who eats Neveilos to anger [Hash-m] is Pasul [for testimony].

Question: Why wasn't this taught in Sanhedrin (27b, among those Pasul for testimony)?

Answer: Also the borrower was not taught [explicitly]. He is included in "one who lends [with Ribis]", like it explains there in the Gemara that "Malveh b'Ribis" is a loan that comes with Ribis. (All parties to it are disqualified.)

Suggestion: The case is, the Ribis is not recognized in the document. Rather, he wrote Stam "Ploni borrowed 100 from Almoni", and the witnesses thought that it was all principal, and afterwards it became known that there was Ribis in it!

Rejection: In Bava Metzi'a (72a), R. Yochanan answers regarding the Mishnah that predated loan documents are Pesulim "it can even be like Rabanan. This is a decree lest he collect from the first date [written in the document]";

If the Ribis is not recognized in the document, also in the case of a document with Ribis, we should decree lest he collect also the Ribis as if it were principal!

Suggestion: [Documents with Ribis] are Kesherim, for this is not Suma. Since the Ribis is recognized in the document, he will not collect the Ribis through this document;

Implied question: The Mishnah in Bava Metzi'a (75b) says that the witnesses transgress a Lav!

Answer: That is when the Ribis is not recognized in the document.

Rebuttal: It says in our Sugya and in Bava Kama (30b) that from the time of writing, he did Suma. If so, through this document he transgresses a Lav!

Answer #1: People think that "Lo Sesimun" applies to the lender, borrower and Arev (guarantor), but not the witnesses. Therefore, they are not disqualified;

This is like we say (Bava Metzi'a 5b) that people think that "Lo Sachmod" applies to [coveting something and taking it] without money. (Really, one who forcibly takes it and pays transgresses, but since he is unaware, he is not disqualified.)

Answer #2: The case is, there are witnesses that they (the witnesses on the loan) were mortally coerced.

Observation: This can answer a similar question about predated loan documents. Some establish it like R. Meir, but according to Rabanan, they are Kesherim;

Question: And even R. Meir disqualifies only due to a fine. What is the reason? The witnesses are Pesulim, for they signed a predated document!

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

Answer #2: There, the case is, they say "we erred about the year of the king."

Pesak (Ri): The Halachah follows Rabanan.

Implied question: We hold like R. Meir's decrees (Eruvin 47a)!

Answer: This is only regarding his decrees, but not his fines.

Support: For this reason, Bahag ruled like R. Meir regarding [one who married] a woman pregnant with or nursing another man's baby.

Implied question: Why don't we bring the Mishnah there? They establish also it like this! He returns not only the excess...

Answer: This is because it is resolved only through Ravin bar Rav Nachman's Beraisa.

We bring it according to the version that it is Dina. According to the version that they fined Heter due to Isur, we cannot bring [a proof] from here, for here a fine does not apply;

If the buyer took more than he should have, we should not fine him for this, for why should he know how much is there?

Assertion: The text should not say like is written in a minority of Seforim in the answer here "who says that he mixed in?", for if so, this connotes that it is brought according to the version that it is a fine.