Exodus 12:29-30 Ex. 12:29-30
29 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. 30 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.
Numbers 33:4 Num. 33:4
For the Egyptians buried all their firstborn, which the LORD had smitten among them: upon their gods also the LORD executed judgments.
(Relation)