In the Apocryphal Book of Wisdom there is a remarkable study of this plague, regarded as retribution in kind. It avenges the oppression of Israel. “For when unrighteous men thought to oppress the holy nation, they being shut up in their houses, the prisoners of darkness, and fettered with the bonds of a long night, lay exiled from the eternal Providence” (xvii. 2). It expresses in the physical realm their spiritual misery: “For while they supposed to lie hid in their secret sins, they were scattered under a thick veil of forgetfulness” (ver. 3). It retorted on them the illusions of their sorcerers: “as for the illusions of art magick, they were put down.... For they, that promised to drive away terrors and troubles from a sick soul, were sick themselves of fear, worthy to be laughed at” (vers. 7, 8). In another place the Egyptians are declared to be worse than the men of Sodom, because they brought into bondage friends and not strangers, and grievously afflicted those whom they had received with feasting; “therefore even with blindness were these stricken, as those were at the doors of the righteous man.” (xix. 14–17). And we may well believe that the long night was haunted with special terrors, if we add this wise explanation: “For wickedness, condemned by her own witness, is very timorous, and being pressed by conscience, always forecasteth grievous things. For”—and this is a sentence of transcendent merit—“fear is nothing else than a betrayal of the succours that reason offereth” (xvii. 11, 12). Therefore it is concluded that their own hearts were their worst tormentors, alarmed by whistling winds, or melodious song of birds, or pleasing fall of waters, “for the whole world shined with clear light, and none were hindered in their labour: over them only was spread a heavy night, an image of that darkness which should afterward receive them: yet were they unto themselves more grievous than the darkness” (vers. 20, 21). Isaiah, too, who is full of allusions to the early history of his people, finds in this plague of darkness an image of all mental distress and spiritual gloom. “We look for light, but behold darkness; for brightness, but we walk in obscurity: we grope for the wall like the blind, yea, we grope as those that have no eyes: we stumble at noonday as in the twilight” (lix. 10). Here the sinful nation is reduced to the misery of Egypt. But if she were obedient she would enjoy all the immunities of her forefathers amid Egyptian gloom: “Then shall thy light rise in darkness and thy obscurity as the noonday” (lviii. 10); “Darkness shall cover the earth, and gross darkness the people, but the Lord shall arise upon thee, and His glory shall be seen upon thee” (lx. 2). And, indeed, in the spiritual light which is sown for the righteous, and the obscuration of the judgment of the impure, this miracle is ever reproduced.