21-23. Stretch out thine hand toward heaven, that there may be darkness—Whatever secondary means were employed in producing it, whether thick clammy fogs and vapors, according to some; a sandstorm, or the chamsin, according to others; it was such that it could be almost perceived by the organs of touch, and so protracted as to continue for three days, which the chamsin does [HENGSTENBERG]. The appalling character of this calamity consisted in this, that the sun was an object of Egyptian idolatry; that the pure and serene sky of that country was never marred by the appearance of a cloud. And here, too, the Lord made a marked difference between Goshen and the rest of Egypt.

     24-26. Pharaoh called unto Moses, and said, Go ye, serve the Lord—Terrified by the preternatural darkness, the stubborn king relents, and proposes another compromise—the flocks and herds to be left as hostages for their return. But the crisis is approaching, and Moses insists on every iota of his demand. The cattle would be needed for sacrifice—how many or how few could not be known till their arrival at the scene of religious observance. But the emancipation of Israel from Egyptian bondage was to be complete.

     28. Pharaoh said, . . . Get thee from me—The calm firmness of Moses provoked the tyrant. Frantic with disappointment and rage, with offended and desperate malice, he ordered him from his presence and forbade him ever to return.