Iah of the Hebrews is plainly the Iacchos (Bacchus) of the Mysteries; the God "from whom the liberation of souls was expected -- Dionysus, Iacchos, Iahoh, Iah." Aristotle then was right when he said: "Jon was Oromasdes and Ahriman Pluto, for the God of heaven, Ahura-mazda, rides on a chariot which the Horse of the Sun follows." And Dunlap quotes Psalm 68:4, which reads:

Praise him by his name Iach
Who rides upon the heavens, as on a horse,

and then shows that "the Arabs represented Iauk (Iach) by a horse. The Horse of the Sun (Dionysus)." Iah is a softening of Iach, "he explains." The Hebrews express the idea of LIFE both by a ch and an h; as chiach, to be, hiah, to be; Iach, God of Life, Iah, "I am." http://www.blavatsky.net/magazine/theosophy/ww/additional/christianity/IAO.html