Exodus 12:21-23

Darby Translation

²¹ And Moses called all the elders of Israel, and said to them, Seize and take yourselves lambs for your families, and kill the passover.

²² And take a bunch of hyssop, and dip [it] in the blood that is in the bason, and smear the lintel and the two door-posts with the blood that is in the bason; and none of you shall go out of the door of his house until the morning.

²³ And Jehovah will pass through to smite the Egyptians; and when he sees the blood on the lintel, and on the two door-posts, Jehovah will pass over the door, and will not suffer the destroyer to come into your houses to smite [you].