Reference for Bava Batra 307:4

רב חסדא ורבה בר רב הונא אמרי ראיה בקיום השטר קא מיפלגי במודה בשטר שכתבו צריך לקיימו דר"מ סבר מודה בשטר שכתבו אינו צריך לקיימו ורבנן סברי מודה בשטר שכתבו צריך לקיימו

is required;<span class="x" onmousemove="('comment',' So that the validity of the deed shall not in any way be dependent on the donor's own word. ');">¹³</span> for R. Meir is of the opinion [that] where one admitted that he wrote a deed,<span class="x" onmousemove="('comment',' And he only disputes its present force, by pleading, for instance, in the case of a deed of a gift, that he was lying sick when he made the gift, or, in the case of a note indebtedness, that he repaid the debt. ');">¹⁴</span> no [independent] attestation is required<span class="x" onmousemove="('comment',' Hence, the deed spoken, of in our Mishnah is valid, and the donor must bring witnesses as proof that he was a sick man at the time the gift was made. ');">¹⁵</span> and the Rabbis<span class="x" onmousemove="('comment',' V. n. 3, supra ');">¹⁶</span>

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