Exodus 12:25

You shall take a bunch of hyssop, and dip it in the blood that is in the basin, and strike the lintel and the two door posts with the blood that is in the basin. None of you shall go out of the door of his house until the morning.

For the LORD will pass through to strike the Egyptians; and when he sees the blood on the lintel, and on the two door posts, the LORD will pass over the door, and will not allow the destroyer to come in to your houses to strike you.

You shall observe this thing for an ordinance to you and to your sons forever.

It will happen, when your children ask you, ‘What do you mean by this service?’

that you shall say, ‘It is the sacrifice of the LORD’s Passover, who passed over the houses of the children of Israel in Egypt, when he struck the Egyptians, and spared our houses.’”

The people bowed their heads and worshiped.

The children of Israel went and did so; as the LORD had commanded Moses and Aaron, so they did.