Reference for Chullin 249:37

אלא מאי חד שמא הוא

But surely if the marrow within can restore [the flesh] outside it, why is it that the thigh-bone of a carcass or of a dead reptile, if not pierced, is clean?<span class="x" onmousemove="('comment',' It is surely regarded as a whole limb, for even if it has no marrow or flesh at present, it will be invested with these later on; of what avail is it, therefore, that the bone is stopped up?');">²¹</span>

Jastrow

Jastrow

Jastrow

Jastrow

Jastrow

Jastrow

Jastrow