Oneiromancy

Oneiromancy is a form of divination based upon dreams; it is a system of dream interpretation that uses dreams to predict the future.

Biblical
Dreams occur throughout the Bible as omens or messages from God:
 * Jacob dreams of a ladder to heaven (Genesis 28);
 * his son Joseph dreamed of his future success (Genesis 37) and interpreted the dreams of the Pharaoh of Egypt (Genesis 41);
 * Solomon conversed with God in his dreams;
 * Daniel interpreted dreams (in the Book of Daniel);
 * Joseph, husband of Mary, was directed to flee to Egypt (Matthew 2);
 * Paul was told to go to Macedonia (Acts 16).

what

Classical
Aristotle and Plato discuss dreams in various works. Artemidorus gives a list of authors mentioned in his Oneirocritica, the longest of the ancient dreambooks. All of the referenced works are lost, but fragments are preserved in Artemidorus and other ancient authors. Achmet wrote an edition of Artemidorus' Oneirocritica in addition to his own. Astrampsychus was the pseudonymous author of a number of divinatory, magical and medical works, including an Oneirocriticon.