Passage 9.26.7
γεγονέναι δὲ ἀπὸ Ἐρεχθέως αὐτόν. Θεσπιεῦσι δὲ ἐν τῇ πόλει Σαώτου Διός ἐστι χαλκοῦν ἄγαλμα· ἐπιλέγουσι δὲ ὡς λυμαινομένου τὴν πόλιν ποτὲ αὐτοῖς δράκοντος προστάξειεν ὁ θεὸς τὸν κλήρῳ τῶν ἐφήβων κατὰ ἔτος ἕκαστον λαχόντα δίδοσθαι τῷ θηρίῳ. τῶν μὲν δὴ διαφθαρέντων μνημονεύειν τὰ ὀνόματα οὔ φασιν· ἐπὶ δὲ Κλεοστράτῳ λαχόντι τὸν ἐραστὴν αὐτοῦ Μενέστρατον λέγουσιν ἐπιτεχνήσασθαι.
That he himself was descended from Erechtheus. In the city of Thespiae there is a bronze image of Zeus Saotas. They relate that when a dragon once ravaged their city, the god commanded them yearly to give the beast the youth selected by lot from among the citizens. They say that they do not preserve the memory of the names of those who perished; but when Cleostratus was chosen by lot, his lover Menestratus, they say, devised a stratagem.