Genesis 15:12

A deep sleep, or ecstasy, like that of Adam, chap. ii. 21, wherein God revealed to him the oppression of his posterity in Egypt, which filled him with such horror (Menochius) as we experience when something frightful comes upon us suddenly in the dark. This darkness represents the dismal situation of Joseph, confined in a dungeon; and of the Hebrews condemned to hard labour, in making bricks, and obliged to hide their male children, for fear of their being discovered, and slain. Before these unhappy days commenced, the posterity of Abram were exposed to great oppression among the Chanaanites, nor could they in any sense be said to possess the land of promise, for above 400 years after this prophetic sleep. (Haydock)