Reference for Chullin 148:52

איבעיא להו

R'Simeon B'Lakish said: We do not reckon here the first and second degree of uncleanness,<span class="x" onmousemove="('comment',' The foetus and the dam are one entity so that the foetus assumes the same degree of uncleanness as its dam.');">²⁷</span>

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