It is indeed! It happens during one of the first three (3!) seasons of supernatural, and Dean grins after saying it.
Sam also says the iconic #bah line later on in the series…
All of this happens within the first five seasons, though it may pop up later on as well, I can’t remember the entire series word-for-word, lol.
bah has been guessed! Guesses are no longer accepted for this and there will be a sneak peek for it coming soon!