If asked why we eat matza on Pesach, most would answer, as does Rabban Gamliel in the haggadah, that it is to commemorate the fact that we were chased out of Egypt and our bread had no time to rise; it is a symbol of redemption. This explanation, though, is not so simple. A close read of the verses in Exodus shows that God actually commanded the nation to eat matza for seven days, before they actually left Egypt. Thus, regardless...