Reference for Niddah 29:46

ל"ש אלא שאין לה וסת

applies only where the husband came and found her within her usually clean period.<span class="x" onmousemove="('comment',' I.e., within thirty days after her last observation of a discharge. After the thirty days, since most women have monthly periods, intercourse must be preceded by an examination. ');">⁴¹</span>

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