Êxodo 12:13

13 The blood will be a sign for you on the houses where you are, and when I see the blood, I will pass over you. No destructive plague will touch you when I strike Egypt.

13 And the blood will be a sign on the houses where you are: when I see the blood I will go over you, and no evil will come on you for your destruction, when my hand is on the land of Egypt.