Swine.

The association or idea of a pig is an animal which really has no discernment nor desire to live cleanly, rather it highly prefers to live in the filth, and “bathe” itself in this filth. It eats and sleeps and lives happily in its own urine and excrement. The Bible associates this with great uncleanness and displeasure in God’s eyes.

[David Cox]

Swine.

The Jewish people had nothing to do with pigs, but these animals still received much attention in the Bible. In (Psalm 80:13), Israel’s enemies were likened to a “boar out of the woods.” Vicious wild pigs (boars) ranged throughout Palestine. Owners of vineyards hated them, because they devoured grapes and trampled their vines. Dogs and men alike feared their razor-sharp tusks. In modern times, the boar is the largest game animal in Israel.

Domesticated pigs (swine) were also raised in Palestine– by Gentiles or unorthodox Jews. Pigs were ceremonially unclean, supposedly because they did not “chew the cud.” The symbol of greed and filth, pigs symbolized a person’s unredeemed nature (2 Pet. 2:22). Jesus told a story of a prodigal son who really hit bottom when he had to take care of hogs and even eat food intended for them (Luke 15:15-16).

Source: [Anon-Animals]