Talmud

I don't think this is what he meant, because at the beginning of the sign he claimed that the person who is the debtor is also defined as a relative, and yet he has a law against him, and if so, why does he hate a witness? Therefore, throughout the entire sign he brings evidence that he is a power of trust, not a trust of "Why should I lie?" And this law against the witness is one of the pieces of evidence for this. And he also wants to explain the Rashbam's method in Shatra Zeifa based on this division. I would be grateful if the Rabbi could go over his words there in his free time.

There is no connection. The migo to the distant party turns his claim into a good claim, but he does not become a witness in this. This is a victory in the claim and not in the evidence. On the other hand, the migo to the relative is the migo who came to turn him into a witness who is admissible evidence, and this the migo cannot do to the relative because with a relative it is a problem of admissibility and not loyalty.
This has nothing to do with the question of loyalty or why should I lie.

I definitely agree with the rabbi's excuse for his question, but that doesn't seem to me to be what he's saying there. He claims there that his entire explanation regarding this is my son and a priest is only if we understand that Megan is a force of loyalty and there's no reason for me to lie. And regarding Tra Zeifa, he writes it in the letter 12.

I would be happy if the rabbi looked at the letter 12 there. He really connects it to the investigation of the power of loyalty, and why should I lie?

I looked again and this is exactly what he writes there. See, for example, the concluding sentence that distinguishes between an incompetent witness and a kosher witness who testified falsely.
And what this implies in understanding the law of Migo is really not necessary. It seems to me correct even if it is about what I should lie about. And perhaps his intention is that if the Migo had what I should lie about, then we would treat it as evidence even if it did not qualify his testimony. Here is the Migo's testimony that stands on its own. But the power of loyalty is not evidence but rather gives fidelity to the claim of the person who testifies, and as a relative he has loyalty but is an incompetent witness (problem of admissibility).
Note: Throughout his remarks he (like other recent ones) creates disputes about whether Migo is what I should lie about or the power of loyalty, which is something that cannot be said. It is clear that the law of what I should lie about also exists in Migo. At most, one can argue about the second law.

Thanks for the explanation and response.
Indeed, the method of the latter to completely reject the issue of why should I lie presented is quite puzzling, and moreover, the Kobash links this to the Amoraic divisions on the issue of Shatra Zeipa, but in any case, it is difficult to find a way that explains all the issues on this subject.
Did the Rabbi understand the explanation he offers (Letter 12) in the words of the Rashbam on the issue of Shatra Zeipa, which the Rashbam writes (Lev. 2: DD "Amai") and Zl: "...and I do not understand the rest of what he should lie about in the Gemara that two claims can be true, the one that he claims and the one that he could have claimed but did not claim. That is why I am saying that, but I do not understand why he should lie in place of witnesses, since all his power and authority on this ground is by the fact that he is a bill of exchange, and as it is said, why should he lie about a bill of exchange...does he not admit that the bill of exchange is invalid..." And all the Rishonim were stuck in the words of the Rashbam, because that is how it is with all of them, that in the end, when I claim the current claim, it turned out that the basic claim was false, so the Rishonim offered quite a few explanations. They are stuck in their thoughts (Yosef Rosh's reasoning) and the compiler offers an explanation. I would be happy if the rabbi could explain it to me.

The division is the same division that I wrote to you above. Indeed, he has something to lie about here too, but he has no power of loyalty. You want to give him the benefit of the forged bill witnesses who could say that they are real (that the bill is not forged). But even if he had said so, the benefit would not have been due to his claim but rather due to witnesses, and now we know that he has no such witnesses. In contrast, in a regular bill, the benefit is due to the claim and not due to witnesses.
In other words: witnesses to a bill are disqualified from the law because they are ‘and not from their written mouth’. Although there is usually a bill law that makes them valid witnesses. But when it is known that the bill is invalid, then there is no bill law here and in any case the testimony in it does not exist, and therefore cannot give force to the claim of a bill above the law.

Yes, but even in a regular Migo, where winning is based on the strength of the claim, the entire winning is still based on the fact that I had the power to claim falsehood, but after I claimed my peace and settled, it turned out that I could never claim falsehood, because it turned out that this claim was false, and if so, I did not have that power, and how is that different from witnesses?

Thank you for the fascinating discussion. I would be happy if the rabbi would recommend Rishonim and Achronim that deal with the subject of migo in depth. One of the most interesting topics I have come across in the Talmud.

There's a whole book, Migo Laws. There's also a booklet of mine here on the site. You can search.

I might refine the question: Why is it only in claims that we find that there is a force of claim, meaning that a claim that could be true even though it ultimately turned out to be a complete lie gives me the power to win the current claim, while the "force of evidence," meaning that evidence that could have been true if I had not admitted it and turned out to be a complete lie, does not give me the power to win the new claim of the above-mentioned one, because both the evidence and the claim ultimately turned out to be a complete lie (I would appreciate it if the rabbi would elaborate a little more, I still don't understand)

I explained. I always have the ability to argue. The fact that I have an argument is not conditioned on it being true. A party's argument is not examined in terms of truth or falsehood, but in terms of his ability to bring it up for discussion. The court will determine whether it is true or false. Therefore, the ability to argue a different argument is the essence of the mechanism of fiduciary power, and it does not matter that the alternative is a lie. But a witness or a deed that does not exist does not exist. There you need to have a witness or a deed in order for it to give fiduciary power.

If a litigant has the ability to bring up a claim that is a complete lie, then why, on the grounds that it is denied by witnesses, does he not have the ability to bring it up for discussion? Why wouldn't he have a migo there too? And why is this claim considered to have the ability to make it even if it is a lie? After all, it is forbidden for a litigant to make false claims, just as it is forbidden for me to forge bills, etc.

He definitely brings it up for discussion, even in such a case. And in the discussion, the verdict is decided against him because of the witnesses.

Yes, but he must have a lawyer and be trustworthy, just as in the case where there is a party's admission that the claim is false, he is also trustworthy despite the party's admission, so even now, even though there are witnesses against him, because he has the ability to claim, he must be trustworthy as well.
And why is a claim defined according to the ability to claim and not according to the consideration of whether it is true or not?

Why should he be loyal? He has a Migo but there are witnesses against him.
I think we are repeating ourselves. I explained what I could, and now I'm completely lost.

Anyway, thank you very much and sorry for the digging.