why is the first man hanged? what does elie say he remembers about the evening after the hanging?

The first man to be executed had stolen two plates of soup. Strong and muscular, he is unafraid at his own execution and shouts "Long live liberty! A curse upon Germany!" right before dying. Although Eliezer is surrounded by death all the time at the concentration camps, he is overwhelmed by this man's solitary execution. Elie remembers the soup tasting like coarpses.