Komentarz do Powtórzonego Prawa 17:6

שנים עדים או שלשה [BY THE MOUTH OF] TWO WITNESSES OR THREE [WITNESSES, SHALL HE THAT IS WORTHY OF DEATH BE PUT TO DEATH] — But if evidence can be established by two witnesses to what end does it (Scripture) mention to you explicitly that it may be established by three? Scripture does so in order to compare the evidence of three witnesses to that of two (to make the same law apply to both cases). How is it in the case of two? Their evidence forms one testimony; so, too, does the evidence of three (or many) witnesses form one testimony and they cannot be declared “plotting witnesses” unless all of them are proved to be “plotting witnesses” (Makkot 5b).

AT THE MOUTH OF TWO WITNESSES, OR THREE WITNESSES, SHALL HE THAT IS TO DIE BE PUT TO DEATH. “If the evidence can be sustained by two witnesses, why did Scripture specify ‘three?’ It is to liken three to two: just as the evidence of two witnesses forms a single unit of testimony, so does the evidence of three, constitute a single unit of testimony and they are not subject to the law of plotting witnesses [which declares that whatever they plotted to do to their brother should be done to them]⁷⁶See further, 19:19. unless all three are proven to be plotters.”⁷⁷But if only one or two of the three witnesses were proven to be false, the evidence is void, and both, the accused and the witnesses are free, and the punishment for plotting witnesses is not imposed, provided all witnesses form a single unit of testimony. The same principles apply even to one out of a hundred witnesses (Makkoth 5b). This is Rashi’s language. So also the principle [of a single unit of testimony] applies if one of the witnesses is found to be a kinsman [and hence ineligible to testify] or to have some other disqualification — the testimony of all is void. If they are proven to have been plotting witnesses, [in which case] all of them are subject to the death-penalty or payment of money [as the case may be, and the third witness cannot claim immunity because of his argument that even had he not testified the evidence of the first two witnesses was sufficient to sustain the charge], since the main intent of Scripture was to liken the evidence of three witnesses to that of two in every respect, according to the opinion of our Rabbis.⁷⁸Makkoth ibid.
And the Gaon Rav Saadia⁷⁹On Rav Saadia see Vol. II, p. 99, Note 230. On the title Gaon see ibid., p. 521, Note 74. Rav Saadia’s comment is quoted here by Ibn Ezra. said, by way of the plain meaning of Scripture, that the interpretation of the verse is as follows: “two witnesses, or three judges who [officially] accept the testimony of the two witnesses.”⁸⁰Rav Saadia holds that even in capital cases which require a court of twenty-three judges, witnesses need not testify in the presence of all the judges; it is sufficient that they testify in the presence of three judges who may receive their testimony on behalf of the full court. The phrase at the mouth of two witnesses, or three witnesses thus means: “upon the testimony of two witnesses who appear before the entire court of twenty-three judges, or by the word of the three judges who officially accepted the testimony of the witnesses and later relayed it to the entire court — shall the one that is to die be put to death. Ramban will refute this interpretation of the Gaon, for there is in the verse etc. But there is in the verse no mention of acceptance of the testimony; instead, it refers explicitly to witnesses. But it seems to me that the Gaon erred in his [statement of this] law, for testimony in capital cases cannot be accepted except in the presence of a Sanhedrin of twenty-three judges [and not, as Rav Saadia holds, before only three judges]! Rather, the plain meaning of the verse is that the condemned man shall be put to death at the mouth of two witnesses if no more are there, or at the mouth of three witnesses if three witnesses are to be found there. Scripture thus states: when it will be told thee, and thou hear it⁵⁸Verse 4 here. you are to inquire diligently into the matter by means of the testimony of all the witnesses found there. Thus if we heard that he transgressed in the presence of three people, we should send for them and have them all come to court and testify. The same law applies to a hundred, for by hearing the words of them all, the truth will become clear. But if not more [than two] were present, or they [the others] left and are not to be found, then two are sufficient.

על פי שנים עדים או שלושה, even if the charge is idolatry, the entire testimony is disqualified if one of the witnesses is found to be inadmissible. We do not rule that seeing there are a sufficient number of reliable and legally admissible witnesses left, we proceed with the trial on that basis.