Reference for Chullin 154:9

לעולם טומאת אוכלין ושאני עור חמור דמאיס:

but where there was a foetus within we have no apprehension that it contained another foetus.<span class="x" onmousemove="('comment',' I.e., there is no reasonable ground to assume that in that part of the afterbirth which had come out there was another foetus, and that this afterbirth belonged to it, so that this afterbirth belonging to a born foetus would be forbidden. We assume rather that this afterbirth belongs to the foetus that is found within it, and which has not yet come out of the womb, so that the afterbirth is permitted.');">⁴</span>

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