One interesting practice frequently encountered in this genre of literature [referring to texts primarily on magical/practical kabala] involves induced dreams. This is usually referred to as a “Dream Request” (Shaalat Chalom), where one poses a question and attempts to induce an answer to appear in a dream. The practice itself is very ancient, alluded to even in the Talmud, and examples are found from as early as the Tenth Century. While the methods for inducing dreams are often purely magical, there are some that have important meditative overtones. This is particularly significant because of the general relationship between prophecy, enlightenment and dreams.
--Aryeh Kaplan, Meditation and Kaballah, p 157