The Lord said to Moses and Aaron in the land of Egypt ... "take some of the blood [of the lamb], and put it on the two doorposts and the lintel of the houses in which they eat them. They shall eat the flesh that night, roasted; with unleavened bread and bitter herbs they shall eat it ... The blood shall be a sign for you, upon the houses where you are; and when I see the blood, I will pass over you, and no plague shall fall upon you to destroy you, when I smite the land of Egypt."Exodus 12:1-13
Bless, + O Lord God, this creature, chalk, and let it be a help to mankind. Grant that those who will use it with faith in your most holy name, and with it inscribe on the doors of their homes the names of your saints, Casper, Melchior, and Baltassar, may through their merits and intercession enjoy health in body and protection of soul; through Christ our Lord.