Leviticus 11:4

4Nevertheless these shall ye not eat of. He more clearly expresses what he had previously glanced at, viz., that an animal, although it may ruminate, shall not be clean unless it also cleaves the hoof; and, on the other hand, that the cloven hoof will not be sufficient unless combined with rumination. In these words Moses taught that partial and imperfect purity must not be obtruded upon God. If any choose to think that rumination is the symbol of internal purity, and the cloven hoof of external, his opinion will be a probable one. Since this distinction has occurred to my mind, although I have no taste for subtle speculations, I have thought it well to mention it, yet leaving it free for any one to accept it or not. Meanwhile we must hold it as certain, as I have lately said, that God demands perfect cleanliness, undefiled by any admixture. But the prohibition was most onerous to the Jews with respect to swine’s flesh, because it is very well adapted for food, not only as being a pleasant accompaniment of other meats, but because the working-classes are fed upon it at a smaller cost. In this point, therefore, the religion of the Jewish people was especially proved. For, when the soldiers of Antiochus desired to force the people to an entire renunciation of the Law, they only urged them to eat swine’s flesh (42) And hence the famous witticism of Augustus, “I would rather be Herod’s pig than his son;” (43) because, whilst he abstained from pork, he was the murderer of his children. But, in order that the Jews might observe this prohibition more strictly, the very touch was also forbidden them; so that it was not only wicked to taste swine’s flesh, but even to touch it with their hands after the animal was killed. The same rule did not apply to beef or mutton; for it is necessary to handle the meat which is appointed for our food.