Reference for Bava Metzia 37:16
אמר אביי הכי קאמר איזו היא מתנת בריא שהיא כמתנת שכיב מרע דלא קני אלא לאחר מיתה כל שכתוב בה מהיום ולאחר מיתה
but now that she has come [with the bill] to take away [the fruit of her property which I bought from her husband] let her go and bring proof when the bill of divorcement came to her hand! But in the case of a note of indebtedness the buyer will not come to demand [proof]. He will say [to himself]: As the Rabbis gave him back the note of indebtedness it is obvious that the purpose for which they gave it to him was [to enable him] to take away [the debtor's sold property from the buyer, and] this shows that the Rabbis made sure of the matter,<span class="x" onmousemove="('comment',' I.e., the Rabbis made sure that the creditor was legally entitled to seize the debtor's sold property. ');"><sup>15</sup></span>