Exodus 12:17-20

“Keep the Festival of Unraised Bread! This marks the exact day I brought you out in force from the land of Egypt. Honor the day down through your generations, a fixed festival to be observed always. In the first month, beginning on the fourteenth day at evening until the twenty-first day at evening, you are to eat unraised bread. For those seven days not a trace of yeast is to be found in your houses. Anyone, whether a visitor or a native of the land, who eats anything raised shall be cut off from the community of Israel. Don’t eat anything raised. Only matzoth.”