Reference for Niddah 106:17

מתקנה

R. Zera enquired of R. Assi: Do stains<span class="x" onmousemove="('comment',' According to Rabbi who attributes a stain to an observation of blood if the latter took place within twenty-four hours, and does not regard the woman's uncleanness as having begun at the time the article (on which the stain was found) had been washed, ');">¹⁶</span>

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