Commentary on the First Alcibiades of Plato (Cambridge, University Library, MS Kk.5.27)

...with them at his bedside: Aristophanes and Sophron. He himself also composed such an epigram for Aristophanes:
"The Graces, seeking to find a sanctuary which would not fall, found the soul of Aristophanes."
He satirized him in the dialogue Symposium, as having benefited from comedy. For having made him hymn Love, he introduces him as falling into the hiccups, and not being able to complete the hymn. He made tragic poems, and dithyrambic ones, and some others, all of which he burned, having experienced the discourse of Socrates, saying, "Hephaestus, come forth here; Plato now has need of you." A certain grammarian, Anatolius, once said the verse here and was well-regarded, as if Hephaestus were the ruler standing over the city. He said it to him thus: "Hephaestus, come forth here; the city now has need of you." They say that when Socrates was about to receive him, he saw in a dream that a wingless swan sat upon his knees. And immediately having grown wings, it flew up into the air and emitted a clear cry, so as to charm all who heard it. This indicated the future fame...