And they shall take of the blood, and put it on the two side posts and on the upper door post of the houses, in which they shall eat it.
All Commentaries on Exodus 12:7 Go To Exodus 12
Basil the Great
Moses caused the doorposts of the Israelites to be signed with the blood of a lamb; but you have given us a sign, the blood itself of a Lamb without blemish, slain for the sin of the world. Ezekiel says that a sign was given on the foreheads of the persons.