Luke 15:15-16

And he went and hired himself out to a resident of the country, and he sent him into his fields to tend pigs.

2 Peter 2:22

What has happened to them shows the truth of the proverb, "A dog returns to what he has vomited up, and a sow that has washed goes back to wallow 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 hired himself out to a resident of the country, and he sent him into his fields to tend pigs.
2 Peter 2:22
What has happened to them shows the truth of the proverb, "A dog returns to what he has vomited up, and a sow that has washed goes back to wallow in the mire."