Parallel
Exodus 11:5
Brenton's English Septuagint · Berean Standard Bible
And every first-born in the land of Egypt shall die, from the first-born of Pharao that sits on the throne, even to the first-born of the woman-servant that is by the mill, and to the first-born of all cattle.
and every firstborn son in the land of Egypt will die, from the firstborn of Pharaoh who sits on his throne, to the firstborn of the servant girl behind the hand mill, as well as the firstborn of all the cattle.