Exodus 13:3-13

So Moses said to the people, “This is a day to remember forever—the day you left Egypt, the place of your slavery. Today the LORD has brought you out by the power of his mighty hand. (Remember, eat no food containing yeast.) On this day in early spring, in the month of Abib, you have been set free. You must celebrate this event in this month each year after the LORD brings you into the land of the Canaanites, Hittites, Amorites, Hivites, and Jebusites. (He swore to your ancestors that he would give you this land—a land flowing with milk and honey.) For seven days the bread you eat must be made without yeast. Then on the seventh day, celebrate a feast to the LORD. Eat bread without yeast during those seven days. In fact, there must be no yeast bread or any yeast at all found within the borders of your land during this time. “On the seventh day you must explain to your children, ‘I am celebrating what the LORD did for me when I left Egypt.’ This annual festival will be a visible sign to you, like a mark branded on your hand or your forehead. Let it remind you always to recite this teaching of the LORD: ‘With a strong hand, the LORD rescued you from Egypt.’ So observe the decree of this festival at the appointed time each year. “This is what you must do when the LORD fulfills the promise he swore to you and to your ancestors. When he gives you the land where the Canaanites now live, you must present all firstborn sons and firstborn male animals to the LORD, for they belong to him. A firstborn donkey may be bought back from the LORD by presenting a lamb or young goat in its place. But if you do not buy it back, you must break its neck. However, you must buy back every firstborn son.