Luke 15:15-16

And he went and joined himself to one of the citizens of that country; and he sent him into his fields to feed swine.

2 Peter 2:22

It hath happened to them according to the true proverb, The dog returned to his own vomit; and, The sow that was washed, to her wallowing in the mire.

Treasury of Scripture Knowledge

Summary

And the swine, because it divideth the hoof, yet cheweth not the cud, it is unclean unto you: ye shall not eat of their flesh, nor touch their dead carcase.

Bible References

The swine

Luke 15:15
And he went and joined himself to one of the citizens of that country; and he sent him into his fields to feed swine.
2 Peter 2:22
It hath happened to them according to the true proverb, The dog returned to his own vomit; and, The sow that was washed, to her wallowing in the mire.