It is told of certain great individuals that they would experience a vision that began in a dream, in the middle of which they woke up, and the vision continued while they were awake.
Most of the prophets received their prophecy that way.
The prophet would enter a state that is beyond consciousness, from which he would slide to the conscious reception of the prophecy.
Prophecy is a certain degree of consciousness but one that cannot be attained in the ordinary state of being.
—Rabbi Adin Steinsaltz