And they shall take of the blood,.... Of the lamb, being received into a basin, Ex 12:22:and strike it on the two side posts; with a bunch of hyssop dipped into it:and on the upper doorpost of the houses, wherein they shall eat it; but not on the posts of those houses, the inhabitants of which joined with their neighbours in eating it; though Levi Ben Gersom thinks they were sprinkled as the rest; but to what purpose, when there were no Israelites, and no firstborn in them?
the two side posts were the posts of a folding door, on which the two folds were hung, and the upper doorpost is what is afterwards called the lintel, Ex 12:23 and has its name in Hebrew from looking out; for, as Aben Ezra says, there was a window over the door, as is the custom throughout the whole country of the Ishmaelites or Arabians; and so Schindler says , which perhaps he took from him, that the word signifies either a lintel, or a little window over the door, through which it might be seen who called or knocked at the door; and adds, in Egypt, as now in Arabia, there were windows over the doors of houses.
The sprinkling the blood of the paschal lamb was typical of the sprinkling of the blood of Christ upon the hearts and consciences of his people, and of their peace, safety, and security by it from the wrath of God, and the vengeance of divine justice; of the further use of this rite, see Ex 12:22, Aben Ezra mentions it as the opinion of some, that the sprinkling of the blood on those places was to show that they slew the abomination of the Egyptians openly; but he himself gives a much better reason for this rite, namely, that it was to be a propitiation for everyone that ate in the house, and was a sign to the destroyer, that he might look upon it in like manner, as it is said Eze 9:4, "set a mark, &c."
this seems to be peculiar to the passover in Egypt, and was not used in later times. Lex. Pentaglott. col.