Read Exodus 11:5 Using Other Translations
And all the firstborn in the land of Egypt shall die, from the firstborn of Pharaoh that sitteth upon his throne, even unto the firstborn of the maidservant that is behind the mill; and all the firstborn of beasts.
and every firstborn in the land of Egypt shall die, from the firstborn of Pharaoh who sits on his throne, even to the firstborn of the slave girl who is behind the handmill, and all the firstborn of the cattle.
All the firstborn sons will die in every family in Egypt, from the oldest son of Pharaoh, who sits on his throne, to the oldest son of his lowliest servant girl who grinds the flour. Even the firstborn of all the livestock will die.