Plutarch, De genio Socratis
Goodwin, Ed.

This, Phidolaus, was my notion of Socrates's Daemon, whilst he lived and since his death; and I look upon all they mention about omens, sneezings, or the like, to be dreams and fooleries. But what I heard Timarchus discourse upon the same subject, lest some should think I delight in fables, perhaps it is best to conceal. By no [p. 407] means, cried Theocritus, let's have it; for though they do not perfectly agree with it, yet I know many fables that border upon truth; but pray first tell us who this Timarchus was, for I never was acquainted with the man. Very likely, Theocritus, said Simmias; for he died when he was very young, and desired Socrates to bury him by Lampocles, the son of Socrates, who was his dear friend, of the same age, and died not many days before him. He being eager to know (for he was a fine youth, and a beginner in philosophy) what Socrates's Daemon was, acquainting none but Cebes and me with his design, went down into Trophonius's cave, and performed all the ceremonies that were requisite to gain an oracle. There he stayed two nights and one day, so that his friends despaired of his return and lamented him as lost; but the next morning he came out with a very cheerful countenance, and having adored the God, and freed himself from the thronging inquisitive crowd, he told us many wonderful things that he had seen and heard; for this was his relation.