C. F. Keil and Franz Delitzsch on Daniel 2:19

Dan 2:19

In answer to these supplications, the secret was revealed to Daniel in a night-vision. A vision of the night is not necessarily to be identified with a dream. In the case before us, Daniel does not speak of a dream; and the idea that he had dreamed precisely the same dream as Nebuchadnezzar is arbitrarily imported into the text by Hitz. in order to gain a “psychological impossibility,” and to be able to cast suspicion on the historical character of the narrative. It is possible, indeed, that dreams may be, as the means of a divine revelation, dream-visions, and as such may be called visions of the night (cf. Dan 7:1, Dan 7:13); but in itself a vision of the night is a vision simply which any one receives during the night whilst he is awake.“Dream and vision do not constitute two separate categories. The dream-image is a vision, the vision while awake is a dreaming - only that in the latter case the consciousness of the relation between the inner and the outer maintains itself more easily. Intermediate between the two stand the night-visions, which, as in Job 4:13, either having risen up before the spirit, fade away from the mind in after-thought, or, as in the case of Nebuchadnezzar (Dan 2:29), are an image before the imagination into which the thoughts of the night run out. Zechariah saw a number of visions in one night, Dan 1:7; Dan 6:15. Also these which, according to Dan 1:8, are called visions of the night are not, as Ew. and Hitz. suppose, dream-images, but are waking perceptions in the night. Just because the prophet did not sleep, he says, Daniel 4, 'The angel awaked me as one is awaked out of sleep.'“ - Tholuck’s Die Propheten, u.s.w., p. 52.