Comentario sobre Levítico 3:4

הכסלים — Flancs in O. F. — It speaks of the fat which is on (על) the kidneys being also on (על) the flanks because the fat that is upon the kidneys is, when the animal is living, on the uppermost part of the flanks, and they (the kidneys) are in a downward position. This is the fat which is under the loins — what are called lombles in O. F.; it is that white fat which is visible upon the upper part of the flanks, but on their lower part the flesh covers it, (and this latter portion of the fat is therefore not upon but under the flanks).

היותרת, a growth on top of the liver.

Separating. The separation (the diaphragm) which divides between the respiratory organs and the intestines is called in the Talmud “the lobe of the liver.”