Exodus 12:21-30

Then Moses called together all of Israel’s elders and said to them, “Go pick out one of the flock for your families, and slaughter the Passover lamb. Take a bunch of hyssop, dip it into the blood that is in the bowl, and touch the beam above the door and the two doorposts with the blood in the bowl. None of you should go out the door of your house until morning. When the LORD comes by to strike down the Egyptians and sees the blood on the beam above the door and on the two doorposts, the LORD will pass over that door. He won’t let the destroyer enter your houses to strike you down. You should observe this ritual as a regulation for all time for you and your children. When you enter the land that the LORD has promised to give you, be sure that you observe this ritual. And when your children ask you, ‘What does this ritual mean to you?’ you will say, ‘It is the Passover sacrifice to the LORD, for the LORD passed over the houses of the Israelites in Egypt. When he struck down the Egyptians, he spared our houses.’” The people then bowed down and worshipped. The Israelites went and did exactly what the LORD had commanded Moses and Aaron to do. At midnight the LORD struck down all the first offspring in the land of Egypt, from the oldest child of Pharaoh sitting on his throne to the oldest child of the prisoner in jail, and all the first offspring of the animals. When Pharaoh, all his officials, and all the Egyptians got up that night, a terrible cry of agony rang out across Egypt because every house had someone in it who had died.