“Adar bears the same relation to Mul-lil that Merodach bears to Ea. Each alike is the son and messenger of the older god.
But whereas the errands upon which Merodach is sent are errands of mercy and benevolence, the errands of Adar are those that befit an implacable warrior. He contends not against the powers of darkness, like Merodach, for the father whose orders he obeys is himself the ruler of the powers of darkness; it is against mankind, as in the story of the Deluge, that his arms are directed. He is a solar hero who belongs to the darkness and not to the light.
It is thus that one of his brothers is “the first-born” of Mul-lil, Mul-nugi, “the lord from whom there is no return.” Mul-nugi is the lord of Hades, the god who is called Irkalla in the legend of the Descent of Istar, and out of whose hands there is no escape.
It may be that he is but another form of the Moon-god, since the Moon-god, we are told, was also the eldest son of Mul-lil. But the name by which the Moon-god went at Nipur was one that signified “the god of glowing fire.”
It is curious to find the mythologists identifying this “god of glowing fire” with Adar; but the error was natural; both alike were sons of Mul-lil, and both alike represented the great orbs of heaven.
The chief seat, however, of the worship of the Moon-god was not Nipur but Ur (the modern Mugheir). Here stood the great temple the ruins of which were partially explored by Loftus.
Already in the oldest documents that have come from thence, the god to whom the temple was consecrated is identified with the Moon-god of Nipur. Already he is termed “the first-born of Mul-lil.” The spread of the cult of Mul-lil, therefore, and of the magic which it implied, must have made its way as far south as Ur in a very remote age.
But we have no reason for believing that the Moon-god of Ur and the Moon-god of Nipur were originally one and the same. Each Babylonian town, large and small, had its own local Moon-god, whose several names are recorded on a broken tablet.
The forms under which the Moon-god was worshipped in Babylonia were as numerous as the forms of the Sun- god himself.
What seems yet more singular to the comparative mythologist is that, according to the official religion of Chaldea, the Sun-god was the offspring of the Moon-god.
Such a belief could have arisen only where the Moon-god was the supreme object of worship. It is a reversal of the usual mythological conception which makes the moon the companion or pale reflection of the sun. It runs directly counter to the Semitic Baal-worship.
To the Semite the Sun-god was the lord and father of the gods; the moon was either his female consort, or, where Semitic theology had been influenced by that of Chaldea, an inferior god.”
A.H. Sayce, Lectures on the Origin and Growth of Religion as Illustrated by the Religion of the Ancient Babylonians, 5th ed., London, 1898, pp. 153-5.