Hastings' Dictionary of the Bible (1898)
SWINE, Deut 14:8, or HOG, was unclean by the ritual law, and an object of utter abhorrence to the Jews. Hence the employment of the prodigal son implies the most contemptible degradation. Luke 15:15. Eating the flesh of swine is mentioned among the sinful practices of the Jews. Isa 65:4; Isa 66:17. The filthy habits of this animal illustrate one feature in the character of sinners. 2 Pet 2:22. The herd of swine miraculously destroyed, Matt 8:32, perhaps belonged to Jews, and, if so, were of course kept in violation of their own law. Lev 11:7.
To cast "pearls before swine," Matt 7:6, is not more vain and wasteful than to offer the words of truth and wisdom to those who are known to despise them, and who would only return the offer with insult and abuse. As the Moslems hold the hog in fully as great abhorrence as do the Jews, it is very rarely that this animal is seen in Palestine or Mohammedan countries.