Incubation (ritual)

Incubation is the religious practice of sleeping in a sacred area with the intention of experiencing a divinely inspired dream or cure. Incubation was practised by many ancient cultures. In perhaps the most well known instance among the Hebrews, found in 1 Kings 3, Solomon went to Gibeon "because that was the most renowned high place to offer sacrifices." There "the Lord appeared to Solomon in a dream at night," and Solomon asked God for the gift of an understanding heart. Among the members of the cult of Asclepius, votive offerings found at ritual centres at Epidaurus, Pergamum, and Rome detail the perceived effectiveness of the method. Incubation was adopted by certain Christian sects and is still used in a few Greek monasteries. Modern practices for influencing dream content by dream incubation utilise more research-driven techniques, but they sometimes incorporate elements reflecting these ancient beliefs.

...
Wikipedia