Celsus tells the story of Aristeas

Let us see also what Celsus says after this, as he sets out marvels from the histories which in themselves look incredible, yet which he does not disbelieve, at least so far as his words go. First comes the story of Aristeas of Proconnesus, about whom he says this: "Then Aristeas of Proconnesus: he vanished from among men in so supernatural a way, appeared again plainly, long afterwards visited many parts of the world and reported marvels, and Apollo enjoined the Metapontines to count Aristeas among the gods; yet no one any longer regards this man as a god."

He seems to have taken the story from Pindar and Herodotus. For now it is enough to set out the words of Herodotus from the fourth book of his Histories, which run thus about him (Herodotus, Histories 4.14–15): "Where Aristeas, who said these things, came from, I have told; and the account I heard of him in Proconnesus and Cyzicus I shall tell. They say that Aristeas, who was inferior in birth to none of the citizens, went into a fuller's shop in Proconnesus and died there, and that the fuller locked up his workshop and went off to tell the dead man's relatives. When the report that Aristeas was dead had already spread through the city, a man of Cyzicus who had come from the town of Artace disputed it with those who were saying it, declaring that he had met Aristeas as he was going toward Cyzicus and had spoken with him. While he was disputing it hotly, the dead man's relatives came to the fuller's shop with what was needed to take up the body; but when the room was opened, Aristeas was to be seen neither alive nor dead. In the seventh year afterwards he appeared in Proconnesus and composed the verses which the Greeks now call the Arimaspea, and having composed them he vanished a second time.

"This is what these cities say. But this I know happened to the Metapontines in Italy two hundred and forty years after the second disappearance of Aristeas, as I found by reckoning in Proconnesus and in Metapontum. The Metapontines say that Aristeas himself appeared to them in their country and bade them set up an altar to Apollo, and beside it a statue bearing the name of Aristeas of Proconnesus. For he told them that theirs was the only country of all the Italian Greeks to which Apollo had come, and that he himself, who was now Aristeas, was following him; but at that time, when he followed the god, he was a raven. Having said this he vanished; and the Metapontines say that they sent to Delphi and asked the god what the apparition of the man might be. The Pythia bade them obey the apparition, saying that if they obeyed, it would go better for them. They accepted this and carried it out. And to this day there stands a statue bearing the name of Aristeas beside the very image of Apollo, with laurels around it; the image is set up in the marketplace. So much, then, for Aristeas."