Passage 9.26.6
τραπομένῳ δὲ ἀπὸ τοῦ Καβειρίου τὴν ἐν ἀριστερᾷ καὶ προελθόντι ὡς πεντήκοντα σταδίους Θέσπια ὑπὸ τὸ ὄρος τὸν Ἑλικῶνα ᾤκισται. θυγατέρα δὲ εἶναι Θέσπιαν λέγουσιν Ἀσωποῦ καὶ ἀπὸ ταύτης κληθῆναι τὴν πόλιν, οἱ δὲ Θέσπιόν φασιν ἐξ Ἀθηνῶν ἐλθόντα τὸ ὄνομα τῇ πόλει δοῦναι·
Turning away from the Cabeirion and proceeding on the road that lies to the left for about fifty stadia, Thespiae lies situated beneath Mount Helicon. They say that Thespia was a daughter of Asopus, and from her the city derived its name; others maintain that Thespius, having come from Athens, gave the city its name.