Exodus 12:29-32

And it came to pass, that at midnight the LORD smote all the firstborn in the land of Egypt, from the firstborn of Pharaoh that sat on his throne unto the firstborn of the captive that was in the dungeon; and all the firstborn of cattle. And Pharaoh rose up in the night, he, and all his servants, and all the Egyptians; and there was a great cry in Egypt; for there was not a house where there was not one dead. And he called for Moses and Aaron by night, and said, Rise up, and get you forth from among my people, both ye and the children of Israel; and go, serve the LORD, as ye have said. Also take your flocks and your herds, as ye have said, and be gone; and bless me also.