Reference for Bava Batra 97:1

אין נאמנים מודעא היו דברינו אין נאמנין

accepted. Also if the witnesses to a deed [of sale] say, We only wrote [under reservation of] a moda'ah<span class="x" onmousemove="('comment',' I.e., before signing the deed, we ascertained that the seller was selling under duress and intended to annul the sale. ');">¹</span>

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