Bava Batra

If, however, it is objected  [that, since the writing on the document had been] erased [once, it might] be erased again,  [it may be replied that anything which] has been erased once is not like [that which] has been erased twice.  But [is there no cause] to apprehend that ink might first be poured on the place of the witnesses,  and this  would be erased,  so that when the text  is subsequently erased  the lower and the upper sections would represent  a repeated erasure?  — Abaye replied: Rab is of the opinion [that] Witnesses [must] not sign on an erasure unless the erasure was made  in their presence. An objection was raised: [A deed] the text  [of which is written] on [clean] paper  and its witnesses on an erasure is valid. Is [there no cause] to apprehend that [the text] might be erased, and any [terms] one desires substituted,  and [thus] there would result [a deed] the text  and witnesses of which [appear] on an erasure?  — They  write as follows:  'We witnesses signed on an erasure and the text is written on paper'. Where, [however], do they write [this]? If below,  [surely] one [can] cut it off! If above,  one [can] erase it!  They write [it]  between the signatures.  If so, explain the second clause: [A deed] the text  [of which appears] on an erasure and its witnesses on [clean] paper is invalid.  Why, [it may be asked,] should it be invalid? Let them in this case  also write thus: 'We witnesses signed on paper and the text [is written] on an erasure'. Would you now also reply [that as the writing] was [once] erased,  one might again erase it?  Surely, you said [that] what was erased once is not like that which was erased twice! — This  [has been said in the case only] where the witnesses are signed on an erasure.  Where, [however], the witnesses are not signed on an erasure but on [clean] paper [the difference  can] not be detected.  But let any  scroll be brought, [on which some writing could] be erased, and compared!  — The erasure on one scroll is not [always] like the erasure on another scroll.  Let, then, the signatures of the witnesses be accepted by the court,  and be erased and compared!  — R. Hoshaia replied: An erasure of one day's [standing] is not like an erasure of two days [standing]. Let it stand [for some time]!  — R. Jeremiah replied: Precaution had to be taken [to provide] against an erring court. R. HANINA B. GAMALIEL SAID: A FOLDED [DEED] ETC. Rabbi raised an objection against the statement  of R. Hanina b. Gamaliel: