Reference for Niddah 29:20

הוא דאמר כשמאי דאמר

[it could be retorted:] Should not then<span class="x" onmousemove="('comment',' In order to avoid the possible mistake that even within the shorter interval, when the woman had the rag in her hand, the Rabbis hold the man to be clean. ');">²⁰</span>

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