Reference for Niddah 79:21

ורבי שמעון נפקא ליה מדתני תנא קמיה דרב ששת

implies that even if she bore in the same manner only as she conceived<span class="x" onmousemove="('comment',' A mashed foetus (cf. supra 26a, 27b). ');">²⁰</span>

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