In every Mel Brooks movie, whether about men in tights, balls in space, or the history of the world, there is a joke reserved to make the “goyim” belly laugh at the Jewish expense and to make the Jews smirk (groan) with acknowledgment at the knock from an insider (that would be Brooks, a.k.a. Melvin Kaminsky).
The joke will be something generic and obvious, playing off the oldest Jewish stereotypes paraded endlessly during the Borscht Belt era