Exodus 12:21-22

New International Version

²¹ Then Moses summoned all the elders of Israel and said to them, “Go at once and select the animals for your families and slaughter the Passover^(A) lamb. ²² Take a bunch of hyssop,^(B) dip it into the blood in the basin and put some of the blood^(C) on the top and on both sides of the doorframe. None of you shall go out of the door of your house until morning.