The god Apollo was the solar god of the heaven during the day, and the Lord of Death in the underworld at night. His latter form became the Jewish Apollyon, Spirit of the Pit (Revelation 9:11). Apollo-Python was the serpent deity in the Pit of the Delphi oracle who inspired the seeress with mystic vapors from his nether world. Abaton was the Greek word for Pit, which the Hebrews changed to Abaddon, which later became synonymous with the Christian hell.
Abaton, also called mundus or earth-womb, was a real pit, regularly placed under or in pagan temples. Those entering it wished to "incubate" or sleep there overnight in magical imitation of the incubatory sleep of the womb, to be visited by an "incubus" or spirit who brought prophet dreams. Novice priests endured longer periods of incubation to pantomime the experiences of death, burial, and rebirth from Mother Earth. Once initiated in this manor, they sought to gain the skill of oneiromancy.
Assyrian priests derived similar powers after a journey in the Pit. They then put on the priestly coat of many colors, signifying communion with the Goddess under her oneiromantic name of Nanshe. The identical burial-and-resurrection ritual is found in the lives of many ancient sages. One was the Pythagorean philosopher Thales of Miletus, said to be one of the Seven Wise Men of the ancient world, who acquired his intellectual skills through communion with the Goddess of Wisdom in an abaton. A.G.H.
Walker, Barbara G., The Woman's Encyclopedia of Myths and Secrets, New York, HarperCollins, 1983, p. 6