One day the pope decided to throw all the Jews out of Rome...

He made an announcement to the Jewish community: "Send me your smartest scholar to convince me why I should let the Jewish people stay and I may reconsider my stance." The Roman Jewish community sent Rabbi Moshe, a 78 year old Hebrew school teacher and, according to everyone but himself, the smartest Jew in Rome.
The Pope and Moshe meet in a large conference hall in the Vatican attended by everyone that could fit in the room. Since neither party speaks each other's language, they elect to have their debate using hand symbols. The Pope begins by holding up three fingers to which Moshe only raises his index finger. The Pope then makes a circular motion with one finger around his head. Moshe responds with an aggressive point to the floor. Finally the Pope takes out a bottle of wine and a communion wafer, Moshe removes an apple from his satchel and takes a bite. With this the the Pope throws his hands to the heavens and shouts "the Jews have done it, they may stay in Rome. I can easily tell when I have been beaten."
Later when the Pope convened with his disciples the only thing they wanted to was how the Pope lost, as they couldn't understand what was being "said." "You see," said the Pope "it is all very simple. I held up three fingers to show that God takes on three forms: the father, the son, and the holy spirit. Moshe countered me with one finger to show that God only has one true form. Next, I made a circular motion to show that God was everywhere to which Moshe responded with his gesture towards the floor which meant God is here with us even right now. The third and final gesture of the wine and wafer was to show that Jesus died for our sins. Moshe used the apple to show me that Adam and Eve were the original sinners. It was all very simple."
Meanwhile, over at the synagogue where Moshe took residence, all of Moshe's disciples were curious as to how he won the debate. "Well you see," Moshe grunted "the Pope held up three fingers to tell me the Jews had three days to leave Rome. I told him 'up yours.' He made a waving gesture with his hands telling me that every Jew needed to leave, regardless of where they go. I pointed at the floor to tell him we aren't going anywhere." Moshe resumed what he had been doing before the question arose. His disciples begged him to continue, asking him what the third and final thing meant. Moshe, without looking up from his desk coolly said "And then we had lunch."


This is a joke that was told to me 10 years ago by my very Jewish father. I feel like it never gets old.
Edit: updated punchline based on a suggestion from a commenter.