Reference for Chullin 197:13

וכל איסורין שבתורה במאה

Rabina said: The [exclusion] was necessary only in regard to the side of the cut; for generally it is said t the side of the cut is forbidden<span class="x" onmousemove="('comment',' V. supra 68b. Whenever a matter is partly permitted and partly forbidden and it is necessary to separate these parts, when they are cut away from each other the surface of the cut on the side of the permitted part which was in contact with the forbidden part must be pared off.');">⁹</span>

Jastrow