“As we have said, but few kabalists believe in it, and this doctrine originated with certain astrologers. While casting up the nativities of certain historical personages renowned for some peculiarities of disposition, they found the conjunction of the planets answering perfectly to remarkable oracles and prophesies about other persons born ages later.
Observation, and what would now be termed “remarkable coincidences”, added to revelation during the “sacred sleep” of the neophyte, disclosed the dreadful truth. So horrible is the thought that even those who ought to be convinced of it prefer ignoring it, or at least avoid speaking on the subject.
This way of obtaining oracles was practiced in the highest antiquity. In India, this sublime lethargy is called “the sacred sleep of ***” It is an oblivion into which the subject is thrown by certain magical processes, supplemented by draughts of the juice of the soma.
The body of the sleeper remains for several days in a condition resembling death, and by the power of the adept is purified of its earthliness and made fit to become the temporary receptacle of the brightness of the immortal Augoeides. In this state the torpid body is made to reflect the glory of the upper spheres, as a burnished mirror does the rays of the sun.
The sleeper takes no note of the lapse of time, but upon awakening, after four or five days of trance, imagines he has slept but a few moments. What his lips utter he will never know; but as it is the spirit which directs them they can pronounce nothing but divine truth.
For the time being the poor helpless clod is made the shrine of the sacred presence, and converted into an oracle a thousand times more infallible than the asphyxiated Pythoness of Delphi; and, unlike her mantic frenzy, which was exhibited before the multitude, this holy sleep is witnessed only within the sacred precinct by those few of the adepts who are worthy to stand in the presence of the ADONAI.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 