Exodus 12:24

²²And ye shall take a bunch of hyssop, and having dipped it into some of the blood that is by the door, ye shall touch the lintel, and shall put it upon both doorposts, even of the blood which is by the door; but ye shall not go out every one from the door of his house till the morning.

²³And the Lord shall pass by to smite the Egyptians, and shall see the blood upon the lintel, and upon both the doorposts; and the Lord shall pass by the door, and shall not suffer the destroyer to enter into your houses to smite you.

— Exodus 12:24 —

²⁵And if ye should enter into the land, which the Lord shall give you, as he has spoken, keep this service.

²⁶And it shall come to pass, if your sons say to you, What is this service?