Elihu makes the case that God could use dreams as a way of warning us.

Job 33:14-20
For God speaks in one way, and in two, though man does not perceive it. In a dream, in a vision of the night, when deep sleep falls on men, while they slumber on their beds, then he opens the ears of men and terrifies them with warnings, that he may turn man aside from his deed and conceal pride from a man; he keeps back his soul from the pit, his life from perishing by the sword. “Man is also rebuked with pain on his bed and with continual strife in his bones, so that his life loathes bread,
and his appetite the choicest food.