"Rabbi Schneur Zalman of Liadi taught that when G‑d told Moses that the Jews should take an etrog, He sent messengers to gather them in Calabria. Thus, even as Napoleon wreaked havoc on Europe during his wars of conquest, Rabbi Schneur Zalman sent a messenger to retrieve for him a Calabria citron from Italy."
"When World War I broke out, a Chassid named Avraham Erlanger, living in Switzerland, received a telegram from the fifth Rebbe asking that he arrange a Calabria etrog. Against huge odds, Erlanger managed to obtain a number of Calabria etrogim, which he sent with a messenger all the way to Lubavitch, arriving just in time for the holiday."
