In certain ancient initiations, the final test imposed on an adept who had come through all the preliminary trials successfully was the experience of death and resurrection. For three days and nights, he lay in a sarcophagus while his instructors watched over him, keeping him in a state close to death by means known only to them.
His etheric and astral bodies were released from his physical body so that he could travel throughout space, and during those three days he would visit all the higher and nether regions. He would be astonished, terrified and amazed at what he saw, and he would touch truth.
When he returned, the bonds that bound his etheric and astral bodies to his physical body were totally transformed. Because of this, all that he had seen and experienced remained in his consciousness, and from that moment on, he was able to remember it easily and in detail.