Exodus 13:6-10

MLV(i) 6 Seven days you will eat unleavened bread and in the seventh day will be a feast to Jehovah. 7 Unleavened bread will be eaten throughout the seven days and there will no leavened bread be seen with you, neither will there be leaven seen with you in all your borders.
8 And you will tell your son in that day, saying, It is because of what Jehovah did for me when I came forth out of Egypt. 9 And it will be for a sign to you upon your hand and for a memorial between your eyes, that the law of Jehovah may be in your mouth, because Jehovah has brought you out of Egypt with a strong hand. 10 You will therefore keep this ordinance in its season from year to year.