Exodus 12:19-21

Young's Literal Translation

¹⁹ seven days leaven is not found in your houses, for any [one] eating anything fermented -- that person hath been cut off from the company of Israel, among the sojourners or among the natives of the land;

²⁰ anything fermented ye do not eat, in all your dwellings ye do eat unleavened things.'

²¹ And Moses calleth for all the elders of Israel, and saith unto them, `Draw out and take for yourselves [from] the flock, for your families, and slaughter the passover-sacrifice;