Leviticus 11:3

Whatsoever parteth the hoof, and is cloven-footed - These two words mean the same thing - a divided hoof, such as that of the ox, where the hoof is divided into two toes, and each toe is cased with horn.

Cheweth the cud - Ruminates; casts up the grass, etc., which had been taken into the stomach for the purpose of mastication. Animals which chew the cud, or ruminate, are provided with two, three or four stomachs. The ox has four: in the first or largest, called the ventriculus or paunch, the food is collected without being masticated, the grass, etc., being received into it as the beast crops it from the earth. The food, by the force of the muscular coats of this stomach, and the liquors poured in, is sufficiently macerated; after which, formed into small balls, it is thrown up by the esophagus into the mouth, where it is made very small by mastication or chewing, and then sent down into the second stomach, into which the esophagus or gullet opens, as well as into the first, ending exactly where the two stomachs meet. This is what is termed chewing the cud. The second stomach, which is called the reticulum, honeycomb, bonnet, or king's hood, has a great number of small shallow cells on its inward surface, of a pentagonal or five-sided form, exactly like the cells in a honey-comb; in this the food is farther macerated, and then pushed onward into the third stomach, called the omasum or many-plies, because its inward surface is covered with a great number of thin membranous partitions. From this the food passes into the fourth stomach, called the abomasum, or rede. In this stomach it is digested, and from the digested mass the chyle is formed, which, being absorbed by the lacteal vessels, is afterwards thrown into the mass of blood, and becomes the principle of nutrition to all the solids and fluids of the body. The intention of rumination, or chewing the cud, seems to be, that the food may be sufficiently comminuted, that, being more fully acted on by the stomachs, it may afford the greatest possible portion of nutritive juices. The word cud is probably not originally Saxon, though found in that language in the same signification in which it is still used. Junius, with great show of probability, derives it from the Cambro-British chwyd, a vomit, as it is the ball of food vomited, or thrown up, from the first stomach or paunch through the esophagus into the mouth, which is called by this name. Those who prefer a Saxon derivation may have it in the verb whence our word chew; and so cud might be considered a contraction of chewed, but this is not so likely as the preceding.

Parteth ... - Rather, is clovenfooted and completely separates the hoofs.

11:3 Cloven-footed — That is, divided into two parts only: This clause is added to explain and limit the former, as appears from Leviticus 11:26, for the feet of dogs, cats etc. are parted or cloven into many parts.

And cheweth the cud — Heb. and bringeth up the cud, that is, the meat once chewed, out of the stomach in the mouth again, that it may be chewed a second time for better concoction. And this branch is to be joined with the former, both properties being necessary for the allowed beasts. But the reason hereof must be resolved into the will of the law-giver; though interpreters guess that God would hereby signify their duties, by the first, that of discerning between good and evil; and by the latter, that duty of recalling God's word to our minds and meditating upon it.