Passage 9.17.5
ταῦτα δὲ αἱ πόλεις αὗται πεπιστεύκασιν ἐκ χρησμῶν τῶν Βάκιδος, ἔστι γὰρ καὶ τάδε ἐν τοῖς χρησμοῖς· ἀλλʼ ὁπόταν Τιθορεὺς Ἀμφίονί τε Ζήθῳ τε χύτλα καὶ εὐχωλὰς μειλίγματʼ ἐνὶ χθονὶ χεύῃ θελγομένου ταύροιο κλυτοῦ μένει ἠελίοιο, καὶ τότε δὴ πεφύλαξο πόλει κακὸν οὐκ ἀλαπαδνόν ἐρχόμενον· καρποὶ γὰρ ἀποφθινύθουσιν ἐν αὐτῇ γαίης δασσαμένων, Φώκου δʼ ἐπὶ σῆμα φερόντων.
These cities have trusted these matters because of oracles of Bacis, for it is written also thus in these same oracles: "But whenever a man of Tithorea pours libations and soothing prayers upon the earth to Amphion and Zethus with the sacrifice of a bull, as the bright sun is setting, then truly guard the city from approaching harm, not feeble; for the fruits in it dwindle away when those who divide the land bring offerings to the tomb of Phocus."