Exodus 12:13-15

Young's Literal Translation

¹³ `And the blood hath become a sign for you on the houses where ye [are], and I have seen the blood, and have passed over you, and a plague is not on you for destruction in My smiting in the land of Egypt.

¹⁴ `And this day hath become to you a memorial, and ye have kept it a feast to Jehovah to your generations; -- a statute age-during; ye keep it a feast.

¹⁵ Seven days ye eat unleavened things; only -- in the first day ye cause leaven to cease out of your houses; for any one eating anything fermented from the first day till the seventh day, even that person hath been cut off from Israel.