Reference for Bava Metzia 134:6

רב פפא ורב הונא בריה דרב יהושע אמרי תרוייהו האי משכנתא באתרא דמסלקי אין בעל חוב גובה הימנה ואין הבכור נוטל בה פי שנים ושביעית משמטתה

thereafter, I will make you a full allowance for the crops.' Now, he who forbids the first arrangement will permit the second; but he who forbids [even] the second, on what condition may he [a scholar] have the usufruct? — When it is as the mortgage bonds arranged in Sura, in which it was written, 'On the expiry of a certain number of years this estate reverts [to the debtor] without any payment.<span class="x" onmousemove="('comment',' Converting it into a sale. ');">⁶</span>

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