And when the sun was going down, a deep sleep fell upon Abram; and, lo, an horror of great darkness fell upon him.
A deep sleep, х tardeemaah (H8639)] - a preternatural sleep, produced by God (see the note at Genesis 11:21).
An horror of great darkness. [The Septuagint has fobos skoteinos megas, a great and awful darkness.] The Scripture represents prophetic visions and dreams as distinct things (Numbers 12:6); for, 'between prophetic visions and dreams generally, there appears to exist this radical distinction, that the former, though sometimes physiologically originating in a particular condition of the body, did not exclude the healthy exercise of the mental faculties, and were granted in the waking state; whereas the latter necessarily took place in a state of somnolency, and were connected with brainular affections.
In visions, mind was raised entirely above the influence of material impressions and former reminiscences, and had all its energies concentrated in the intense contemplation of the supernatural objects directly presented to its view; in dreams there was a resuscitation of former ideas, more or less influenced by the condition of the cerebral organ. In the dream which Abram had, the subject was one which had occupied his thoughts during the day-the posterity which God had promised him. Still, while visions and dreams were distinct, there was a close connection between them, so close that, as Henderson ('On Inspiration') has remarked, 'the one species of revelation occasionally merges into the other.' Such was the case in the experience of Abram.
The divine communications first took place in the daytime in a vision, but afterward, at sunset, they continued to be made when 'a deep sleep and a horror of great darkness fell upon him.' 'The statement of the time is meant to signify the supernatural character of the darkness and of the sleep, and to denote the difference between a vision and a dream' (Gerlach). That Abram saw in prophetic ecstasy the servitude of his children in Egypt, represented in a panoramic view before his mental eye, is maintained by Hengstenberg, who thinks that this scenic picture accompanied the prediction made to him, and recorded in the following verses-a prediction remarkable for its specific character, and which bears upon its front the marks of having been uttered before the event to which it refers took place.