Exodus 12:15-18 - The Festival Of Unleavened Bread
15 Seven days shall ye eat unleavened bread: on the very first day ye shall put away leaven out of your houses; for whoever eateth leavened bread from the first day until the seventh day that soul shall be cut off from Israel. 16 And on the first day ye shall have a holy convocation, and on the seventh day a holy convocation: no manner of work shall be done on them, save what is eaten by every person that only shall be done by you.
17 And ye shall keep the feast of unleavened bread; for in this same day have I brought your hosts out of the land of Egypt; and ye shall keep this day in your generations as an ordinance for ever. 18 In the first month, on the fourteenth day of the month, in the evening, ye shall eat unleavened bread until the one and twentieth day of the month in the evening.