'Proverb' in the Bible

Jesus said to them, "No doubt you will quote to me the proverb, 'Physician, heal yourself!' and say, 'What we have heard that you did in Capernaum, do here in your hometown too.'"

They are illustrations of this true proverb: "A dog returns to its own vomit," and "A sow, after washing herself, wallows in the mire."