Rabbi Yosei says: In what case is this statement, that if one of the three witnesses is disqualified the entire testimony is voided, said? It is said with regard to cases of capital law, which are adjudicated stringently. But with regard to cases of monetary law, which are adjudicated more leniently, even if one of the witnesses is disqualified, the testimony will be validated with the testimony of the rest of the witnesses, and if it is sufficient the case can be adjudicated on that basis. Rabbi Yehuda HaNasi disagrees and says: If one of the three witnesses is disqualified the entire testimony is voided in both cases of monetary law and cases of capital law.

And when does one disqualified witness void the entire testimony? Only when the witnesses forewarned them before they performed the transgression, thereby demonstrating their desire to fill the role of witnesses in that case. But when they did not forewarn them, what shall two brothers do in a case where they, together with others, saw someone who killed a person? Will the murderer escape punishment because two relatives happened to be there at the time of the murder and their presence voids the entire testimony? No, the testimony is voided by the presence of relatives or disqualified witnesses only when their intent was to testify. If that was not their intent, they do not void the testimony.

GEMARA: Apropos the statement in the mishna that the halakhic status of one hundred witnesses equals that of two witnesses with regard to the halakha of conspiring witnesses among other halakhot, Rava says: And that is their status only in a case where all the witnesses testified within the time required for speaking a short phrase. If their testimony extended over a longer period, the testimony of the witnesses does not constitute one testimony. Rav Aḥa of Difti said to Ravina: Now, what are the circumstances of the period of time indicated by the words: Within the time required for speaking a short phrase? It is a period whose duration is equivalent to the duration of the greeting of a student to a rabbi: Shalom alekha, rabbi, which means: Greetings to you, my teacher. The duration of the testimony of one hundred witnesses is always greater than the duration of that greeting. How, then, can one hundred witnesses testify within the time required for speaking a short phrase?

Ravina said to him: Rava means that each and every witness must begin testifying within the time required for speaking a short phrase after the other witness completes his testimony. The result is an uninterrupted series of testimonies that combine into a single testimony.

§ The mishna teaches that Rabbi Akiva says: The third witness mentioned in this verse does not come for the judges to be lenient concerning him; rather, its mention comes for the judges to be stringent concerning him and to render his halakhic status like that of these two witnesses who testified with him. And just as with regard to two witnesses, if one of them was found to be a relative or otherwise disqualified their entire testimony is voided, the same is true for a set consisting of numerous witnesses. Rav Pappa said to Abaye: But if that is so, that a relative or other disqualified witness who witnesses an incident voids the entire testimony, the murdered victim should spare the accused from execution because the victim himself witnessed his own murder, and he is considered a disqualified witness because of his personal stake in the verdict. Therefore, the entire testimony should be voided. Abaye said to Rav Pappa: A murderer is executed only when he killed the victim from behind him and the victim did not witness his murder.

Rav Pappa said to Abaye: It is not uncommon for a murder to take place without the knowledge of the victim. But in a case where one is sentenced to death for sodomizing a male, why is he executed? The one who was sodomized should spare the accused from execution. Here too, since the victim witnessed the sodomy, and he is disqualified from bearing witness due to his personal stake in the verdict, the entire testimony should be voided. The Gemara answers: The sodomizer, too, is executed only when he sodomized the victim from behind him, and the victim did not witness the act of sodomy.

Rav Pappa said to Abaye: Although it is possible to construct a scenario where the victim did not witness the act, it is difficult to construct a scenario where the perpetrator did not witness the act. Therefore, the murderer and the one who sodomizes should spare themselves from execution and void the testimony because they witnessed the act, and they are disqualified from bearing witness on the grounds that a person is not capable of testifying about himself. Abaye was silent and was unable to respond. When Rav Pappa came before Rava with this question, Rava said to him: It is written: “According to two witnesses or three witnesses shall a matter be established” (Deuteronomy 19:15); it is with regard to those who establish a matter as legal fact in court that the verse is speaking. It is only witnesses who are relatives or otherwise disqualified who void the entire testimony, not subjects of the matter. Therefore, there is no basis for the questions of Rav Pappa.

§ The mishna teaches that Rabbi Yosei says: In what case is this statement said…what shall two brothers do in a case where they, together with others, saw someone who killed a person? Rabbi Yosei says that it is only with regard to cases of capital law that one disqualified witness voids the entire testimony, and Rabbi Yehuda HaNasi says that this is the halakha even with regard to cases of monetary law. The mishna continues and says that it is only if the witnesses forewarned the perpetrators that they are classified as witnesses capable of voiding the entire testimony. The Gemara poses a question: How do we, the members of the court, formulate what we say to the witnesses in order to ascertain whether their intent was to testify?

Rava says: This is what we say to the witnesses who come to the court: Did you come to observe the proceedings or did you come to testify? If the witnesses say they came to testify, then if one of them is found to be a relative or otherwise disqualified, their entire testimony is voided. If the witnesses say that they came to observe, in that situation, what shall two brothers do in a case where they saw someone who killed a person? It is certainly unusual for those who witnessed the murder to not even attend the court hearing.

With regard to the dispute in the mishna, it was stated that there is an amoraic dispute: Rav Yehuda says that Shmuel says: The halakha is in accordance with the opinion of Rabbi Yosei, and Rav Naḥman says: The halakha is in accordance with the opinion of Rabbi Yehuda HaNasi.