Exodus 12
18 Ref In the first month, from the evening of the fourteenth day, let your food be unleavened bread till the evening of the twenty-first day of the month.
19 Ref For seven days no leaven is to be seen in your houses: for whoever takes bread which is leavened will be cut off from the people of Israel, if he is from another country or if he is an Israelite by birth.
20 Take nothing which has leaven in it; wherever you are living let your food be unleavened cakes.