Exodus 12:23-27

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

And you shall keep this event as an ordinance for you and your children forever.

When you enter the land which the Lord will give you, as He has promised, you shall keep this rite.

And when your children say to you, ‘What does this rite mean to you?’

then you shall say, ‘It is a Passover sacrifice to the Lord because He passed over the houses of the sons of Israel in Egypt when He struck the Egyptians, but spared our homes.’ ” And the people bowed low and worshiped.