Proverbs 26:11

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

2 Peter 2:22

But it is happened unto them according to the true proverb, The dog has 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 a respite, he hardened his heart, and hearkened not unto them; as the LORD had said.

Matthew 12:45

Then he goes, and takes 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 unto 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 a respite, he hardened his heart, and hearkened not unto them; as the LORD had said.
Matthew 12:45
Then he goes, and takes 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 unto this wicked generation.
2 Peter 2:22
But it is happened unto them according to the true proverb, The dog has 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 afterward they turned, and caused the servants and the handmaids, whom they had let go free, to return, and brought them into subjection for servants and for handmaids.