Exodus 12:20-22

New International Version - UK

²⁰ Eat nothing made with yeast. Wherever you live, you must eat unleavened bread.’

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 lamb. ²² Take a bunch of hyssop, dip it into the blood in the basin and put some of the blood on the top and on both sides of the door-frame. None of you shall go out of the door of your house until morning.