Note 224 — THE THEOGONY.
George Chapman translation
Jove sends Iris down.] To this covenant (with Noah) Hesiod alludes: he calls it the great oath. He says that this oath was Iris, or the bow in the heavens; to which the deity appealed when any of the inferior divinities were guilty of an untruth. On such an occasion the great oath of the gods was appointed to fetch water from the extremities of the ocean, with which those were tried who had falsified their word. Bryant.
The words will certainly admit of this construction; but the context directs that the great oath be connected with the Stygian water. The employment of Iris on the mission is still a remarkable coincidence with the diluvian covenant.