Albert Barnes Commentary Job 33:15

"In a dream, in a vision of the night, When deep sleep falleth upon men, In slumberings upon the bed;" — Job 33:15 (ASV)

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 - See the notes at (Job 4:13); compare the introduction to Isaiah, Section 7 (4).

When deep sleep falls 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 most profound repose of the night. The word rendered “deep sleep” (תרדמה tardêmâh) is one that denotes the most profound repose. It is not merely sleep, but it is sleep of the soundest kind - that kind when we do not usually dream; see the notes at (Job 4:13). The Chaldee has here rendered it correctly, עמקתא שינתא - sleep that is deep. The Septuagint renders it, δεινὸς φόβος deinos phobos - dread horror. The Syriac renders this verse, “Not by the lips does he teach; by dreams and visions of the night,” etc.

In slumberings upon the bed - The word rendered “slumberings” (בתנומה bitenumâh) means a light sleep, as contradistinguished from very profound repose. Our word slumber conveys the exact idea. The meaning of the whole is that God speaks to people when their senses are locked in repose - alike in the profound sleep when they do not ordinarily dream, and in the gentle and light slumbers when the sleep is easily broken. In what way, however, they were to distinguish such communications from ordinary dreams, we have no information. It is scarcely necessary to remark that what is said here and elsewhere in the Scriptures about dreams is no warrant for putting any confidence in them now as if they were revelations from heaven.