Exodus 12:22-24

Living Bible

²² Drain the lamb’s blood into a basin, and then take a cluster of hyssop branches and dip them into the lamb’s blood, and strike the hyssop against the lintel above the door and against the two side panels, so that there will be blood upon them, and none of you shall go outside all night.

²³ “For Jehovah will pass through the land and kill the Egyptians; but when he sees the blood upon the panel at the top of the door and on the two side pieces, he will pass over^[a] that home and not permit the Destroyer to enter and kill your firstborn. ²⁴ And remember, this is a permanent law for you and your posterity.