Reference for Bava Batra 339:1

רבן שמעון בן גמליאל סבר אין אותיות נקנות במסירה ורבי סבר אותיות נקנות במסירה

R. Simeon b. Gamaliel holds [that] 'letters' are not acquired by delivery<span class="x" onmousemove="('comment',' The production of the deed is, therefore, useless and the title to the land must rest entirely on the evidence of 'undisturbed possession'. ');">¹</span> and Rabbi holds [that] 'letters' are acquired by delivery.

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