Reference for Bava Batra 307:3
(סימן מניח) רבי מאיר כרבי נתן ורבנן כרבי יעקב
R. Meir [is of the same opinion] as R. Nathan<span class="x" onmousemove="('comment',' That the condition of the person at the time the lawsuit is before the court is the determining factor. And since the donor is then in good health it is assumed that he was in a similar condition when the gift was made. Hence it is for him to bring witnesses who could testify that at that time he was lying sick. ');"><sup>9</sup></span> and the Rabbis<span class="x" onmousemove="('comment',' The Sages of our Mishnah. ');"><sup>10</sup></span> [are of the same opinion] as R. Jacob.<span class="x" onmousemove="('comment',' Who maintains that the gift cannot be taken out of the confirmed possession of its original owner (the donor), unless witnesses can be brought by the donee to testify that at the time the gift was made he was in good health. ');"><sup>11</sup></span> R. Hisda and Rabbah, son of R. Huna, said, 'Proof [is produced] by the attestation of the deed,' [because] they differ [on the question whether, in the case] where a person admitted that he wrote a deed, [independent] attestation<span class="x" onmousemove="('comment',' Before a court. ');"><sup>12</sup></span>