Argonautica

With these words she took an oath by the waters of Styx, which to all the gods is most dread and most awful, that the Harpies would never thereafter again approach the home of Phineus, son of Agenor, for so it was fated. And the heroes yielding to the oath, turned back their flight to the ship. And on account of this men call them the Islands of Turning though aforetime they called them the Floating Islands. And the Harpies and Iris parted. They entered their den in Minoan Crete; but she sped up to Olympus, soaring aloft on her swift wings.

Meanwhile the chiefs carefully cleansed the old man's squalid skin and with due selection sacrificed sheep which they had borne away from the spoil of Amycus. And when they had laid a huge supper in the hall, they sat down and feasted, and with them feasted Phineus ravenously, delighting his soul, as in a dream. And there, when they had taken their fill of food and drink, they kept awake all night waiting for the sons of Boreas. And the aged sire himself sat in the midst, near the hearth, telling of the end of their voyage and the completion of their journey:

"Listen then. Not everything is it lawful for you to know clearly; but whatever is heaven's will, I will not hide. I was infatuated aforetime, when in my folly I declared the will of Zeus in order and to the end. For he himself wishes to deliver to men the utterances of the prophetic art incomplete, in order that they may still have some need to know the will of heaven.