Exodus 11:4-6

Young's Literal Translation

⁴ And Moses saith, `Thus said Jehovah, About midnight I am going out into the midst of Egypt,

⁵ and every first-born in the land of Egypt hath died, from the first-born of Pharaoh who is sitting on his throne, unto the first-born of the maid-servant who [is] behind the millstones, and all the first-born of beasts;

⁶ and there hath been a great cry in all the land of Egypt, such as there hath not been, and such as there is not again.