Reference for Chullin 112:43

ניקב הזפק רבי אומר

Where is this? - R'Bibi B'Abaye said: It is that part of the crop at which point it begins to elongate.<span class="x" onmousemove="('comment',' Lit., 'all that stretches with it', i.e., with the oesophagus. It refers to the point at which the crop begins to taper and to form into the tube of the oesophagus.');">¹⁷</span>

Jastrow

Jastrow

Jastrow

Jastrow

Jastrow