I saw a Simpsons repeat from 1992 a few days ago, the one where Bart and Lisa go to the horrible camp Krusty. It had a joke where Homer said to Marge "We've got all the fireworks we need right here..." (or something like that, referring to love) and then the camera pans over to a picnic basket full of fireworks. They had the exact same joke in the Special Edna episode two weeks ago.
-Blake