Job 33:15

In a dream, in a vision of the night,.... That is, God speaks to men in this way, and which in those times was his most usual way; see Job 4:12; 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, Numbers 12:6; and sometimes directly and immediately to persons themselves, as he did to Abimelech and Laban,

Genesis 20:3;

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, when a man is between sleeping and waking; and now at such a time, when he was laid on his bed in the night season, it was usual for God to come to him in a visionary way, and impress things on his mind; when it was called off front worldly and earthly thoughts and cares, and was calm and serene, and so fit to receive what intimations and instructions might be given this way; see Psalms 4:4. Job had his dreams and night visions, though he seems not to have had any benefit by them, or to have understood them, but was scared and terrified with them, Job 7:14; to which Elihu may have some respect.