The Mishna requires witnesses who can testify that the hidden object which is being carried on Shabbos is merely a knife for Milah. The
Rashash asserts that invalid witnesses (such as Krovim) are ineligible, thereby implying that they would be used for an ordinary testimony. How can this be? The Gemora suggests that the carrier and one other witness are sufficient. Certainly, in an ordinary testimony a person can not testify on his own behalf!?Thank you in advance.
Dov Lew
The RASHASH is addressing the conclusion of the Gemara. The Gemara concludes that when the Mishnah says that "two witnesses" are needed, this means one additional witness together with the carrier himself is sufficient, and when it says "two witnesses" it means two witnesses who are fit to testify somewhere else. The Rashash explains that this comes to exclude two relatives, who are not fit to testify together anywhere. Thus, the other person here must not be a relative of the carrier.
I understand your question to be, why do we need kosher witnesses here? If real testimony is necessary, the carrier should not qualify since he is "Noge'a b'Davar." If not, what is the point of having another kosher witness, that is not a relative?
Your are certainly correct in suggesting that real testimony is not necessary. (This matter is neither a momentary affair, nor a Davar she'ba'Ervah, but an Isur alone. One witness should suffice.) Two are not needed to testify but merely to publicize the fact that the knife was being carried for Milah (as we find with regard to publicizing the protest of the owner of a field, who must protest in front of two, see Bava Basra 39a) for the sake of Chibuv Mitzvah or to prevent Chashad. The reason they may not be relatives according to the Rashash is, perhaps, in order to ensure that the word is properly spread, since relatives have the same group of family members and friends and might not be able to publicize the fact sufficiently.
Be well,
-Mordecai