Ahu (Avestan) [from the verbal root ah consciousness of life; cf Sanskrit asu] Sometimes Ahum, Akhum. The most aware and therefore best prepared to rule in the physical world. Fravashi, on the other hand, is least aware of the material world and yet is the source of awareness and closest to the source of absolute Being. According to later Pahlavi writings Ahu's task is to establish order in the human physical body; therefore it can be considered the ruler in the physical world.
Rumi, 13th century Iranian mystic poet, considers ahu (jan) conscious life, in which the immutable divine knowledge is reflected. Molavi attributes three qualities to jan: consciousness; ability to distinguish between good and evil; and an inclination towards good and resentment towards evil (Massnavi bk 6).
Ferdowsi, 10th century Iranian poet, considers kherad (intellect) the preserver of ahu, the first creation and the integral part of jan. In Mazdean literature ahu corresponds to the first of the five life-giving forces or fires namely: ahu, daena, baudha, urvan, and fravashi in the order of awareness; James Darmesteter translates them respectively as: spirit, conscience, intelligence, soul, and fravashi (Yasna 26, 4). Ahu (Sanskrit) [probably from paro'mhu beyond the range of sight] Invisible, unknown, secret, mysterious; Blavatsky equates it with the Sanskrit eka (one) and Hebrew echod, that which begins an emanation-series from the Unknowable