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.
Warning is here given to Pharaoh of the last and conquering plague which was now to be inflicted. This was the death of all the first-born in Egypt at once, which had been first threatened (Exo 4:23, I will slay thy son, thy first-born), but is last executed; less judgments were tried, which, if they had done the work would have prevented this.
Commenting on Exodus 11:4-10
And all the firstborn in the land of Eygpt shall die,.... By the destroying angel inflicting a disease upon them, as Josephus says (q), very probably the pestilence; however, it was sudden and immediate death, and which was universal, reaching to all the firstborn that were in the families of the Egyptians in all parts of the kingdom: from the firstborn of Pharaoh that sitteth...
And all the first-born in the land . . . shall die--The time, the suddenness, the dreadful severity of this coming calamity, and the peculiar description of victims, among both men and beasts, on whom it was to fall, would all contribute to aggravate its character.