I was thinking about the phrase ‘The pot calling the kettle black’. It comes from a time where cooking was done over open fires and cookware would become visibly ashy. (Fun fact: It first appears and was perhaps coined by Cervantes in Don Quixote!)
What are some other idioms that have lost their literal connection to time? What would be a good modern replacement?
They have the same meaning that you’re trying see if the horse is healthy and the car’s engine is in good condition.