Exodus 29:13-14

And thou shalt take all the fat that covereth the inwards, and the caul {that is} above the liver, and the two kidneys, and the fat that {is} upon them, and burn {them} upon the altar. {the caul: it seemeth by anatomy, and the Hebrew doctors, to be the midriff} But the flesh of the bullock, and his skin, and his dung, shalt thou burn with fire without the camp: it {is} a sin offering.