Proverbs 26:11

As a dog returneth to his vomit, so a fool returneth to his folly.

2 Peter 2:22

But it hath happened to them according to the true proverb, The dog is turned to his own vomit again; and, The sow that was washed, to her wallowing in the mire.

Exodus 8:15

But when Pharaoh saw that there was respit, he hardened his heart, and hearkened not to them, as the LORD had said.

Matthew 12:45

Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also to this wicked generation.

Treasury of Scripture Knowledge

Summary

As a dog returneth to his vomit, so a fool returneth to his folly.

General references

Bible References

A dog

Exodus 8:15
But when Pharaoh saw that there was respit, he hardened his heart, and hearkened not to them, as the LORD had said.
Matthew 12:45
Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also to this wicked generation.
2 Peter 2:22
But it hath happened to them according to the true proverb, The dog is turned to his own vomit again; and, The sow that was washed, to her wallowing in the mire.

General references

Isaiah 28:8
For all tables are full of vomit and filthiness, so that there is no place clean.
Jeremiah 34:11
But afterwards they turned, and caused the servants and the handmaids, whom they had liberated, to return, and brought them into subjection for servants and for handmaids.