Êxodo 12:19

19 For seven days no yeast is to be found in your houses. And anyone, whether foreigner or native-born, who eats anything with yeast in it must be cut off from the community of Israel.

19 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.