Proverbs 26:11

As a dog turneth back to its vomit, so a fool repeateth his folly.

2 Peter 2:22

But that word of the true proverb has happened to them: The dog has turned back to his own vomit; and, The washed sow to her rolling in mud.

Exodus 8:15

And Pharaoh saw that there was respite; and he hardened his heart, and hearkened not to them, as Jehovah had said.

Matthew 12:45

Then he goes and takes with himself seven other spirits worse than himself, and entering in, they dwell there; and the last condition of that man becomes worse than the first. Thus shall it be to this wicked generation also.

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
And Pharaoh saw that there was respite; and he hardened his heart, and hearkened not to them, as Jehovah had said.
Matthew 12:45
Then he goes and takes with himself seven other spirits worse than himself, and entering in, they dwell there; and the last condition of that man becomes worse than the first. Thus shall it be to this wicked generation also.
2 Peter 2:22
But that word of the true proverb has happened to them: The dog has turned back to his own vomit; and, The washed sow to her rolling in mud.

General references

Isaiah 28:8
For all tables are full of filthy vomit, so that there is no more place.
Jeremiah 34:11
But afterwards they turned, and caused the bondmen and the bondmaids whom they had let go free, to return, and brought them into subjection for bondmen and for bondmaids.