Thematic Bible: Firstborn set apart as a

sacrifice every firstborn male offspring to Jehovah. The firstborn male offspring of each of your animals belongs to Jehovah. It will cost you a sheep or a goat to buy any firstborn donkey back from Jehovah. You must break the donkey's neck if you do not buy it back. You must also buy every firstborn son back from Jehovah. In the future when your children ask you, 'What does this mean?' tell them: 'Jehovah used his mighty hand to bring us out of slavery in Egypt.'' read more.
Pharaoh was too stubborn to let us go. Because of this every firstborn male in Egypt-human and animal was killed. This is why we sacrifice every firstborn male to Jehovah and buy every firstborn son back from Jehovah. This festival will be like a mark on your hand and like a band on your forehead, because Jehovah used his mighty hand to bring us out of Egypt.