Reference for Bava Batra 97:3

גופא אמר רב נחמן אמנה היו דברינו אין נאמנין מודעא היו דברינו אין נאמנין

— This is the case where they make a verbal statement to this effect, because a verbal statement cannot invalidate a written deed, but if they write a deed,<span class="x" onmousemove="('comment',' As here, where the moda'ah was recorded in writing before the sale took place. ');">³</span>

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