In the Mysteries the initiate was placed in a deathlike sleep for a period of three days while his spirit endured the ordeal of initiatism in the subtle world. The "temple sleep" was originally implemented in the initiations of Ancient Egypt. The candidate was wrapped in grave clothes and buried in a tomb, and went through a form of ritual death. At the conclusion the hierophant raised the initiate in what amounted to a ritual resurrection from the tomb.
See Mather Walker's Essay : The "Madness" of Don Quixote Eyed Awry