Exodus 12:15-20

15Seven days you shall eat unleavened bread. On the first day you shall remove leaven out of your houses, for if anyone eats what is leavened, from the first day until the seventh day, that person shall be cut off from Israel. 16On the first day you shall hold a holy assembly, and on the seventh day a holy assembly. No work shall be done on those days. But what everyone needs to eat, that alone may be prepared by you. 17And you shall observe the Feast of Unleavened Bread, for on this very day I brought your hosts out of the land of Egypt. Therefore you shall observe this day, throughout your generations, as a statute forever. 18In the first month, from the fourteenth day of the month at evening, you shall eat unleavened bread until the twenty-first day of the month at evening. 19For seven days no leaven is to be found in your houses. If anyone eats what is leavened, that person will be cut off from the congregation of Israel, whether he is a sojourner or a native of the land. 20You shall eat nothing leavened; in all your dwelling places you shall eat unleavened bread.”