Passage 8.15.4
κύαμον μὲν οὖν ἐφʼ ὅτῳ μὴ καθαρὸν εἶναι νομίζουσιν ὄσπριον, ἔστιν ἱερὸς ἐπʼ αὐτῷ λόγος· οἱ δὲ τῷ Φενεατῶν λόγῳ δεξάμενοι τὴν θεόν, Τρισαύλης καὶ Δαμιθάλης, ἐποιήσαντο μὲν Δήμητρος ναὸν Θεσμίας ὑπὸ τῷ ὄρει τῇ Κυλλήνῃ, κατεστήσαντο δὲ αὐτῇ καὶ τελετήν, ἥντινα καὶ νῦν ἄγουσιν. ὁ δὲ ναὸς οὗτος τῆς Θεσμίας σταδίους πέντε μάλιστά που καὶ δέκα ἐστὶν ἀπωτέρω τῆς πόλεως.
For the reason why beans are considered an impure vegetable there exists a sacred account. But those who, according to the tradition of the Pheneatians, once received the goddess, namely Trisaules and Damithales, constructed a temple to Demeter Thesmia beneath Mount Cyllene, and also established rites in her honor, which they celebrate to this very day. This temple of Thesmia is situated roughly fifteen stades from the city.