ט אמר רבי שמעון בן לקיש פדחת פוטרת בכל מקום חוץ מן הנחלה מאי טעמא (דברים כא יז) יכיר אמר רחמנא ור' יוחנן אמר אפי' לנחלה
9 because we do not infer the case of a human being from that of an animal, as the latter has no forepart of female genitals,<span class="x" onmousemove="('comment',' Lit., 'ante-chamber'. Its vagina does not lie between the feet and therefore the coming forth of the head is accounted a birth, for it is open, whereas in the case of a woman, since the legs cover it, the putting forth of the head is not accounted a birth.');"><sup>13</sup></span> and again we do not infer the case of an animal from that of a human being, as the latter's full face is important - have we not learnt this too<span class="x" onmousemove="('comment',' That the putting forth of the head of a human being is regarded as a birth.');"><sup>14</sup></span> in a Mishnah: If an infant came forth in the natural way,<span class="x" onmousemove="('comment',' I.e., the head coming first and not the legs.');"><sup>15</sup></span> [it is not considered a birth] till the greater part of its head comes forth? And what is the greater part of its head? When its forehead comes forth.<span class="x" onmousemove="('comment',' And although the head was withdrawn, and the infant is not born till the next day, we count the period of pure and impure days from the first day when the forehead came forth (Nid. 28a) . Therefore there is no need even in the second clause of the Mishnah to teach us that the putting forth of the head in a human being constitutes a birth, as this is already stated in the Mishnah in Niddah. Why then does the first clause in our Mishnah say 'its head'? Therefore it must not be on account of the second clause, and the reference to the head in the first clause is meant to be taken exactly. Therefore we can deduce from this clause that the emergence of the head of a non-viable birth is considered a birth, exempting the offspring which follows from redemption, contrary to the opinion of Samuel (R. Gershom) .');"><sup>16</sup></span>