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.
All the first-born in the land of Egypt shall die. The time, the suddenness, the dreadful severity of this coming calamity, and the special description of victims, both among men and beasts, on whom it was to fall, would all contribute to aggravate its character. The first-born were selected for the victims of this fatal plague, since, from the pre-eminence attached in ancient times to the primogeniture, they represented the elite of the nation; and the being who displayed his terrible power in the slaughter of the first-born might extend it to the entire destruction of the people.
Maid-servant ... behind the mill. The grinding of the meal for daily use in every household is commonly done by female slaves, and is considered the lowest employment. Two portable millstones are used for the purpose, of which the uppermost is turned by a small wooden handle, and during the operation the maid sits behind the mill. Thus, squatted on the ground, she pours in the grain with one hand, and holds firmly a peg in the stone with the other. The surface of the lower stone is convex, and that of the upper concave; hence, they are fitted to each other, and in being applied to use, the latter is whirled round upon the former, which remains stationary. But one person is commonly required, though when larger stones are employed, as they seem to have been anciently, two work at a mill (Matthew 24:41; Luke 17:35). Those millstones vary from 27 to 30 inches in diameter, and the friction produces a rumbling noise (Jeremiah 25:10).