Exodus 13:7-9

Young's Literal Translation

⁷ unleavened things are eaten the seven days, and any thing fermented is not seen with thee; yea, leaven is not seen with thee in all thy border.

⁸ `And thou hast declared to thy son in that day, saying, `[It is] because of what Jehovah did to me, in my going out from Egypt,

⁹ and it hath been to thee for a sign on thy hand, and for a memorial between thine eyes, so that the law of Jehovah is in thy mouth, for by a strong hand hath Jehovah brought thee out from Egypt;