My father was appointed to the Rabbinate of Berlin a little before Purim, at the end of the First World War. A few days after Purim, he received a letter from a soldier serving at the front. “Most of the soldiers sent to the front never returned. The letter said, “My name is Moishele Cohen. I’m the only matzah baker in my whole home town. If I don’t come home immediately, there won’t be any matzos in my town for Pesach, so please...