He divide the hoof - It is cloven-footed and completely, etc. See Leviticus 11:3 note. Of all the quadrupeds of which the Law forbids the flesh to be eaten, the pig seems to have been regarded as the most unclean. Compare the marginal references. Several other nations have agreed with the Hebrews in this respect: the reason being that its flesh is unwholesome, especially in warm climates.

And the swine - חזיר chazir, one of the most gluttonous, libidinous, and filthy quadrupeds in the universe; and, because of these qualities, sacred to the Venus of the Greeks and Romans, and the Friga of our Saxon ancestors; and perhaps on these accounts forbidden, as well as on account of its flesh being strong and difficult to digest, affording a very gross kind of aliment, apt to produce cutaneous, scorbutic, and scrofulous disorders, especially in hot climates.

And the swine, though he divide the hoof, and be cloven footed,.... Not only its hoofs are parted, but cloven quite through, and so in this respect answers Moses's first descriptive character of clean creatures; though Aristotle (u) and Pliny (w) speak of some kind of swine in Illyricum, Paeonia, and other places, which have solid hoofs; but perhaps these were not properly swine, though so called:
yet he cheweth not the cud; and a learned physician observes (x), that such creatures that chew not the cud, so perfect a chyle cannot be elaborated by them as is by those that chew the cud, and therefore their flesh must be less wholesome; and of the swine, he says (y), they have but one belly, and so there is no rumination or chewing the cud by them; wherefore they are to be placed, and are in a lower degree than the camel, the coney, and the hare; and as they cannot digest the chyle so well as those that chew the cud, and also live upon most sordid and filthy food, the eating of swine's flesh, he observes, must produce many inconveniences to the body, as especially scorbutic, arthritic, scabious, and leprous disorders: so Manetho the Egyptian says (z), that he that eats swine's milk is liable to be filled with the leprosy; and Maimonides (a) gives it as the principal reason of its being forbid the Jews, because it is such a filthy creature, and eats such filthy things:
he is unclean to you: and so it has always been accounted by the Jews, and nothing is more abominable to them, as is even testified by Heathen (b) writers; and in this they have been imitated by many nations, particularly the Egyptians, who, as Herodotus says (c), reckon swine a very filthy creature; so that if anyone does but touch it passing by, he is obliged to plunge himself into a river with his clothes on; and keepers of them may not go into any of their temples, nor do the rest of the Egyptians intermarry with them, but they marry among themselves; the reason of this their abhorrence of swine, Aelianus says (d), is because they are so gluttonous that they will not spare their own young, nor abstain from human flesh; and this, says he, is the reason why the Egyptians hate it as an impure and voracious animal: likewise the Arabians entirely abstain from swine's flesh, as Solinus says (e), who adds, that if any of this sort of creatures is carried into Arabia, it immediately dies; and the same Pliny (f) attests: and so the Phoenicians, the near neighbours of the Jews, would not eat the flesh of them; hence Antoninus is said to abstain from it after the manner of the Phoenicians (g), unless the historian should mean the Jews; also the Gallo-Grecians or Galatians (h); nay, even the Indians have such an abhorrence of it, that they would as soon taste of human flesh as taste of that (i), and it is well known that the Mahometans abstain from it; and they have such an aversion to it, that if any chance to kill a wild pig, for tame they have none, they look on the merit of it to be almost equivalent to the killing a Christian in fight (k): now these creatures may be an emblem of filthy and impure sinners, especially apostates, who return to their former impurities and wallow in them, 2-Peter 2:22.
(u) Hist. Animal. l. 2. c. 1. (w) Nat. Hist. l. 11. c. 46. (x) Scheuchzer. ut supra, (Physic. Sacr. vol. 2.) p. 282. (y) Ib. p. 284. (z) Apud Aelian. de Animal. l. 10. c. 16. (a) Moreh Nevochim, par. 3. c. 48. (b) "Et vetus indulget", &c. Juvenal. Satyr. 6. "nec distare putant", &c. Ib. Satyr. 14. Vid. Porphyr. de Abstinentia, l. 4. sect. 11, 12. (c) Euterpe, sive, l. 2. c. 47. (d) Ut supra. (Apud Aelian. de Animal. l. 10. c. 16.) (e) Polyhistor. c. 46. (f) Nat. Hist. l. 8. c. 52. (g) Herodian. Hist. l. 5. c. 16. (h) Pausan. Achaica, sive, l. 7. p. 430. (i) Ctesias apud Aelian. de Animal. l. 16. c. 37. (k) Pitts's Account of the Mahometans, p. 163.

the swine--It is a filthy, foul-feeding animal, and it lacks one of the natural provisions for purifying the system, "it cheweth not the cud"; in hot climates indulgence in swine's flesh is particularly liable to produce leprosy, scurvy, and various cutaneous eruptions. It was therefore strictly avoided by the Israelites. Its prohibition was further necessary to prevent their adopting many of the grossest idolatries practised by neighboring nations.

The swine has cloven hoofs, but does not ruminate; and many of the tribes of antiquity abstained from eating it, partly on account of its uncleanliness, and partly from fear of skin-diseases.