What was the purpose of and what were people required to do or bring to the passover and feast of unleavened bread?

The Passover and Feast of Unleavened Bread, celebrated by the Israelites, commemorated their liberation from slavery in Egypt. During Passover, families were required to sacrifice a lamb and mark their doorposts with its blood to be spared from the final plague. They were also instructed to eat unleavened bread and bitter herbs, symbolizing their haste in leaving Egypt and the bitterness of slavery. The Feast of Unleavened Bread followed, during which they had to remove all leaven from their homes and eat only unleavened bread for seven days.