Job 33:15

“In a dream, in a vision of the night, etc.] That is, God speaks to men in this way, and which in those times was his most usual way; (see <180412> Job 4:12,13); sometimes he spake to a prophet, a person in public office, and made known his mind and will in this manner to him, that he might deliver it to others, (<041206>Numbers 12:6); and sometimes directly and immediately to persons themselves, as he did to Abimelech and Laban, (<012003>Genesis 20:3 31:24); when deep sleep lieth upon men, in slumberings upon the bed; the former denotes a fast, heavy, and sound sleep, when the senses are all locked up, and there is not the least attention to any outward object; the latter a slight sleep,…”

“slumberings--light is opposed to "deep sleep." Elihu has in view Eliphaz (Job 4:13), and also Job himself (Job 7:14). "Dreams" in sleep, and "visions" of actual apparitions, were among the ways whereby God then spake to man (Gen 20:3).”

“In a dream - This was one of the methods by which the will of God was made known in the early periods of the world; see the notes at Job 4:12-17. And for a fuller account of this method of communicating the divine will, see the introduction to Isaiah, Section 7 (2). In a vision of the night - Notes, Job 4:13; compare the introduction to Isaiah, Section 7 (4). When deep sleep falleth upon men - This may be designed to intimate more distinctly that it was from God. It was not the effect of disturbed and broken rest; not such fancies as come into the mind between sleeping and waking, but the visitations of the divine Spirit in the profoundest repose of the night. The word rendered “deep sleep”…”

“33:15 He speaks in dreams: See, e.g., Gen 15:12; 20:3; 31:24; 40:1–41:36; Dan 2:1-45; Joel 2:28; Acts 16:9-10.”

“a dream: Job 4:13; Gen 20:3, Gen 31:24; Num 12:6; Jer 23:28; Dan 4:5; Heb 1:1 deep: Gen 15:12; Dan 8:18 Job 33:16”