Êxodo 12

21 Then Moses sent for the chiefs of Israel, and said to them, See that lambs are marked out for yourselves and your families, and let the Passover lamb be put to death.

22 And take some hyssop and put it in the blood in the basin, touching the two sides and the top of the doorway with the blood from the basin; and let not one of you go out of his house till the morning.

23 For the Lord will go through the land, sending death on the Egyptians; and when he sees the blood on the two sides and the top of the door, the Lord will go over your door and will not let death come in for your destruction.