John Gill Bible Commentary

And thou shalt take all the fat that covereth the inwards,.... That covered the skin or caul, in which the bowels are contained, called the "omentum", which generally has a pretty deal of fat upon it: and the caul that is above the liver; which seems to design the diaphragm or midriff; but the Septuagint renders it, "the lobe of the liver"; and Ben Melech says it is to be interpreted with the liver, for he says he took a little of the liver with the caul: and the two kidneys, and the fat that is upon them, and burn them upon the altar; the Targum of Jonathan is, lay them in order on the altar; it is not easy to say, since fat is taken both in a good and bad sense, what is designed by the burning of it: as fat often designs the best, it being burned on the altar may signify that the best is to be given to the Lord, and we are to honour him with the best things we have, which should be devoted to his service; or as fat renders insensible, and stupefies and makes men heavy, and inclines to a carnal and vicious disposition, and the inward parts and reins being the seat of carnal desires, affections, and lusts; it may denote that the inward part of man is very wickedness, and that the inward corruptions of nature, and the carnal affections and fleshly lusts, are to be mortified and destroyed, at least the power of them to be subdued and restrained.