(Mishnah): If this [witness] says 'this is my signature, and this is my colleague's (the other witness') signature', and this one says 'this is my signature, and this is my colleague's signature', they are believed;

If this one says 'this is my signature', and this one says 'this is my signature', they need one [who recognizes their signatures] to join with them. Rebbi says so;

Chachamim say, they do not need another to join with them. Rather, a man is believed to say 'this is my signature.'

(Gemara) Question: Why is [the Reisha] needed? (It is obvious!)

Answer: [It is needed] according to Rebbi. Even though Rebbi says that they need another to join with them, he agrees here that they are believed (each is believed about the other's signature).

(R. Ze'ira): It was taught in Maseches Kesuvos in Rav's academy, Rebbi holds that [the witnesses] testify about the document (therefore, we need two witnesses for each signature). Chachamim hold that they testify about the loan (so the two of them suffice).

(Beraisa): One may write testimony that he saw, and testify [based on it] even many years later.

Opinion #1 (R. Chunah): This is only if he remembers the testimony.

Opinion #2 (R. Yochanan): It is even he does not remember his testimony.

R. Chunah holds like Rebbi (if he does not remember the testimony, he is like a stranger testifying about a document. What he wrote by himself is not a document, so his testimony is void.) R. Yochanan holds like Rabanan (even if he knows the testimony only due to what he wrote, he is a witness about the episode. - SEFER NIR)

(R. Ze'ira citing R. Chunah citing Rav): He (one witness) and a stranger do not join [to validate] the second witness' signature.

Question: What is the case?

Answer #1: One [witness who is here] recognizes his own signature and his colleague's signatures, and one (the other witness), no one [here] recognizes his signature (other than the first witness, and one stranger). May his colleague (the witness who is here) join with the stranger to testify about it (and also validate his own signature)?

Rebuttal: About this, did R. Ze'ira citing R. Chunah citing Rav say that he and a stranger do not join [to validate] the second witness' signature?! (Obviously he does not. Three quarters of the testimony is through one witness!)

Answer #2: Rather, he needed to teach about when the two witnesses, one of them, everyone (i.e. two strangers) recognize his own signature, and one (the other witness), no one [here] recognizes his signature (other than the first witness, and one stranger). May his colleague (the witness who is here) be like a stranger, to testify about it [with the other one here who recognizes it]?

[R. Ze'ira taught that he cannot, for] if you will say so, all (really, three quarters of) the testimony is established through one witness (his signature, and his testimony about the other signature).

Support (R. Yudan): This is proper! If two came from a city that is mostly Nochrim, like Susisa; one, all recognize that he is a Yisrael, and one of them, no one recognizes him, only his friend (the known Yisrael) recognizes him. Can he be like a stranger, to testify about him (and then the two of them will testify about a matter)?

[Surely he cannot, for] if you will say so, is it not found that all the testimony is established through one witness?! Also here (R. Zeira's teaching), it would be found that all of the testimony is established through one witness!

Question (R. Chagai citing R. Ze'ira): One witness [testifying] verbally and one witness in a document - do they join?

Question: One witness in a document - is this anything?! (It is not testimony at all!)

Answer: We need to ask about when there were two [signed on the document]. They were able to validate one's signature, but they could not validate the other's signature.

Question (R. Mana): Can one witness in writing obligate [one who contradicts him, to take] a Shevu'ah?

Question: One witness in a document - is this anything?! (It is not testimony at all!)

Answer: We need to ask about when there were two [signed on the document]. They were able to validate one's signature, but they could not validate the other's signature.

Answer: It is like the following (Beraisa). We accept witnesses only if they saw [the testimony] together;

(R. Yehoshua ben Korchah): It is even if they saw one after the other.

(R. Yirmeyah citing R. Shmuel bar Rav Yitzchak citing Rav): Chachamim agree to R. Yehoshua ben Korchah about witnesses of Bechorah (a father said who is his Bechor) and witnesses of Chazakah (Ploni used a particular land for three years).

(R. Ba citing R. Yirmeyah): The same applies to witnesses of Simanim (hairs to establish adulthood).

The following is obvious. If this [witness] says "I saw two hairs on his back", and this one says "I saw two hairs on his back" [they join];

If one says "I saw one hair on his back", and this one says "I saw one hair on his stomach", it has no effect, and all the more so if both of them say "on his back" (perhaps he has only one hair)!

If two say "we saw one hair on his back", and two say "we saw one hair on his stomach", R. Yosi bar Bun and R. Hoshayah brei d'R. Shamai argue about this - one of them says Pasul (they do not join), and one of them says Kosher;

The one who says Pasul, it is because he is like one who testifies about Chetzi Simanim (testimony must be about a full Davar, and not a Chetzi Davar. One lone hair has no significance.) The one who says Kosher, it is because [we know about to him through witnesses. Are we concerned] lest [when the latter pair saw, the first hair already] fell out?! (MEICHAL HA'MAYIM)

If one says "[I saw] two hairs on his back", and one says "two on his stomach", R. Ba says that all (R. Yosi and R. Hoshayah) agree that it is Kosher, and R. Chagai says that all agree that it is Pasul, and R. Yosi says that they argue about this.

R. Yosi (to R. Chagai): R. Yudan says like me.

R. Chagai (to R. Yosi): I argue with [R. Yudan's] Rebbi (R. Ba). All the more so I argue with him!

Support (R. Mana): R. Chagai said properly - if there are four signatures on a document, and it was contested, and this [witness] testified about two of them, and this testified about two of them, does this [validation] help at all? Doesn't every signature need two witnesses about it?!

And here, every Siman needs two witnesses!

R. Chanina learns from years of Chazakah. if one testified that he ate the first, second and third year, and one testified that he ate the fourth, fifth and sixth, does this help at all?

Doesn't every [year of] Chazakah need two witnesses? And here, every Siman needs two witnesses!