And the blood shall be to you for a token upon the houses
where you are
The blood of the passover lamb being sprinkled on the two sideposts and upper doorposts of the houses inhabited by the Israelites, or where they were eating the passover; this should be a sign or token to them of the Lord's making good his promises, to them, and so of their safety, and to the destroying angel not to enter therein, but pass by and save them:
and when I see the blood, I will pass over you;
for which reason this ordinance now instituted was called the passover, because the Lord, on sight of the blood sprinkled, passed over the houses of the Israelites to those of the Egyptians; or "leaped", as Jarchi says, the word signifies, skipped from one Egyptian house to another, passing by that of the Israelites:
and the plague shall not be upon you, to destroy you, when I smite the
land of Egypt,
the pestilence with which the firstborn should be destroyed.