Exodus 12:21-23

International Standard Version

²¹ Then Moses summoned all the elders of Israel and told them, “Choose sheep for your families, and slaughter the Passover lamb. ²² Take a bundle of hyssop and dip it in the blood that is in the basin, and apply some of the blood in the basin to the lintel and the two doorposts. None of you is to go out of the doorway of his house until morning, ²³ because the Lord will pass through to strike down the Egyptians, and when he sees the blood on the lintel and the two doorposts, the Lord will pass over the doorway, and won’t allow the destroyer to enter your houses to strike you down.