Deuteronomy 16:3-4

ECB(i) 3 Eat no fermentation with it; seven days, eat matsah, the bread of humiliation; for you came from the land of Misrayim in haste: so that you remember the day you came from the land of Misrayim all the days of your life. 4 And no yeast is seen with you in all your border seven days; and none of the flesh you sacrifice the first day at evening, stays overnight all night until the morning.