And just as witnesses render other witnesses false, conspiring witnesses only in their presence, because with their testimony they render them liable to be punished, so too, witnesses contradict the testimony of other witnesses only in their presence. Since the signatories to the document are dead, their testimony cannot be contradicted.

Rav Naḥman said to Rav Sheshet: If the first pair of witnesses was before us and the second pair would contradict their testimony, that is contradiction, and we would not consider their testimony and would not collect money with the document, as it is contradicted testimony. Now that they are not before us, and in a case where if they were before us perhaps they would have admitted to the second witnesses that the testimony of the second witnesses is correct, are they deemed credible, and the document that they signed valid?

Rather, Rav Naḥman said in the case where the testimony of the first witnesses is contradicted not in their presence, the ruling is: Establish two witnesses against the two witnesses who contradict their testimony, thereby neutralizing both testimonies, and establish the money in the possession of its owner, just as it was in the case of the property of bar Shatya. As when bar Shatya, a man who suffered from periodic bouts of insanity, sold his property, two witnesses came and said: He sold it when he was insane; and two other witnesses came and said: He sold it when he was sane.

Rav Ashi said in that case: Establish two witnesses against the two witnesses who contradict the testimony of the first pair, and establish the money in the possession of bar Shatya. The Gemara notes: We say that the property remains in the possession of bar Shatya only when he has possession of the property based on the possession of his fathers. However, if he does not have possession of the property based on the possession of his fathers, but he acquired the property himself, we say: He purchased his properties when he was insane, and he sold them when he was insane. He does not have presumptive ownership of them. Therefore, the property remains in the possession of the person to whom bar Shatya sold it.

Rabbi Abbahu disagrees with the opinion of Rav Sheshet and says: Witnesses render other witnesses false, conspiring witnesses only in their presence, but witnesses contradict the testimony of other witnesses not in their presence. And with regard to rendering other witnesses false, conspiring witnesses not in their presence, although it is not effective in rendering them false, conspiring witnesses in the sense that they are punished for their false testimony, in any case, it is a contradiction of their testimony.

§ The Master said in the baraita cited previously: If there are other witnesses who testify that it is their handwriting, or if their handwriting emerges from another place, from a document that one challenged and that was deemed valid in court, these witnesses are not deemed credible. The Gemara infers: From a document that one challenged, yes, the signatures are authenticated and the testimony of the other witnesses is not accepted; however, if one did not challenge the document, no, the document cannot be used to authenticate their signatures. This supports the statement of Rabbi Asi, as Rabbi Asi said: One ratifies a document by authenticating the witnesses’ signatures only from a document that someone challenged and that was deemed valid in court.

The Sages of Neharde’a say: One ratifies a document by authenticating the witnesses’ signatures only from two marriage contracts or from the bills of sale for two fields that those witnesses signed. And those bills of sale are effective only in a case where their owner ate their produce for three years, the requisite period to establish presumptive ownership of the field, and in peace, undisturbed by protest. In that case we can rely on the signatures, and the documents are considered valid.

Rav Shimi bar Ashi said: Authentication of signatures by comparison to other documents can be accomplished specifically when the documents emerge from the possession of another. However, when the documents emerge from the possession of the litigant himself, no, they may not be used to authenticate the signatures. The Gemara asks: What is different in a case where the documents emerge from the possession of the litigant himself that they may not be used to authenticate the signatures? It is that perhaps while the documents were in his possession he learned how to copy the signatures and forged them. If so, also in a case where the documents emerge from the possession of another, perhaps he went and saw the signatures, and came back and forged them. The Gemara answers: In that case, he would not be able to accurately reproduce the signatures to that extent based on memory alone.

§ The Sages taught: A person may write his testimony in a document and testify on its basis even after several years have passed. Rav Huna said: And that is the halakha only if he remembers the testimony on his own and he uses the document merely to refresh his memory with regard to certain details. Rabbi Yoḥanan said: One may rely on that written testimony even if he does not remember the testimony by himself at all. Rabba said: Conclude from this statement of Rabbi Yoḥanan: With regard to these two witnesses who know testimony in a certain case, and one of them forgot the testimony, one witness may remind his fellow witness of the testimony, as according to Rabbi Yoḥanan, even if the witness remembers the testimony only by means of an external stimulus, the testimony is valid.

A dilemma was raised before the Sages: If the litigant himself reminds the witness of the testimony, what is the ruling? Rav Ḥaviva said: Even if the litigant himself reminds the witness, he may testify. Mar, son of Rav Ashi, said: If the litigant himself reminds the witness, he may not testify. And the Gemara concludes that the halakha is that if the litigant himself reminds the witness of the testimony, the witness may not testify, due to the concern that the litigant influenced the nature of his testimony.