Reference for Niddah 29:33

התם אין שור שחוט לפניך הכא יש שור שחוט לפניך

does she not convey uncleanness to the man who had intercourse with her, hence we were informed [that she does convey uncleanness to the man]. Might it not, however, be suggested that the law is so indeed?<span class="x" onmousemove="('comment',' That she does not convey uncleanness to the one who had intercourse with her after the discovery of a bloodstain just as she does not render him unclean retrospectively during the twenty-four hours prior to her having observed a discharge. ');">³⁰</span>

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