Ketubot

Rabbanai, the brother of R. Hiyya b. Abba, came to buy sesame and he said: Thus Samuel said: Witness and judge are joined together. Amemar said: How excellent is this tradition! Said R. Ashi to Amemar: Because the father of your mother  praised it, you also praise it! Raba has already refuted it. R. Safra said [that] R. Abba said [that] R. Isaac b. Samuel b. Martha said [that] R. Huna said, and some say [that] R. Huna said [that] Rab said: If three  sit together to confirm a deed, and two [of them] know  the signatures of the witnesses and one does not know,  before they sign,  they may testify  before him,  and he  [then] signs  [with them]; after they have signed, they may not testify before him and he may not sign. But do we write [the attestation]?  Did not R. Papi say in the name of Raba: The judge's attestation which is written before the witnesses give evidence as to their signatures is invalid, because it looks like a lie? [And] here also it looks like a lie! — But say: Before they have written [the attestation] they may testify before him and he [then] signs [with them]; after they have written [the attestation], they may not testify before him and he may not sign. We may infer from this three things.  We may infer that a witness may be  a judge;  we may [also] infer that, if the judges know the signatures of the witnesses, there is no need to testify  before them;  and [again] we may infer that, if the judges do not know the signatures of the witnesses, it is necessary to give evidence before every one.  R. Ashi demurred to this: Agreed  that we may infer from it that a witness may be a judge, but [how can we infer from it that], if the judges know the signatures of the witnesses, there is no need to testify before them? Perhaps, indeed, I can say to you [that] this is necessary, but it is different here, because the telling  has been fulfilled before one.  And [further, how can we infer from It that], if the judges do not know the signatures of the witnesses, it is necessary to give evidence before every one?  Perhaps, indeed, I can say to you [that] this is not necessary, but it is different here, because the telling  would not have been fulfilled at all. R. Abba sat and reported  this law, that a witness may be a judge. R. Safra [then] objected to R. Abba: If three  saw it  and they are [of] the court, two  shall stand up and set [two] of their fellows  beside the one, and they  shall testify before them,  and [then] they say: Hallowed is the new moon, hallowed; for one person is not believed by himself. Now, if you assume that a witness may be a judge, what do we want all this for? Let them sit in their places  and proclaim  [the new moon] is hallowed! — He said to him: That was also difficult to me, and I asked R. Isaac b. Samuel b. Martha. and R. Isaac [asked] R. Huna, and R. Huna [asked] Hiyya b. Rab, and Hiyya b. Rab [asked] Rab, and he said to them: Leave alone the testimony as to the new moon, [for it is] Biblical, and the confirmation of documents is Rabbinic. R. Abba said [that] R. Huna said [that] Rab said: If three sit to confirm a document and an objection is raised  against one of them,  they  may, before they have signed [the attestation], give evidence regarding him,  and he may [then] sign; after they have signed, they may not give evidence regarding him  and he may not sign. On what ground was that objection raised? If the objection was on the ground of robbery,