Deuteronomy 18:3

Ver. 3. From them that offer a sacrifice— These words may be rendered, This shall be the priest's due from those who slay an animal: for the original word signifies no more than to kill an animal. Genesis 43:16. See Calmet and Ainsworth. Philo, Josephus, and many others, understand this of beasts slain for food in their several towns, not for sacrifice; for as to animals offered in sacrifice, only the breast and the right shoulder are to be given to the priests, but not a word is said of the two cheeks and the maw, by which is thought to be meant the stomach, particularly the lower stomach. According to naturalists, animals which chew the cud have four ducts through which the aliments are conveyed into the intestines, whereof the fourth and lowest, which is called in Greek, η νευστρον eneustron, and in Latin, omasum, is the fattest, and accounted by the ancients a great dainty.