The primary scriptures related to Passover are found in Exodus 12 and Leviticus 23 of the Hebrew Bible (Old Testament). Exodus 12 details the specific instructions for the initial Passover celebration, including the slaughter of a lamb, the application of its blood to the doorposts, and the preparation of the meal. Leviticus 23 further defines Passover as a festival and provides instructions for the Feast of Unleavened Bread