Passage 10.22.11
καί πως ἐπʼ ἐκείνης συνέβαινε τῆς ἡμέρας τήν τε ὁμίχλην κατὰ τοῦ ὄρους καταχεῖσθαι πολλὴν καὶ ἀμαυρὸν ὑπʼ αὐτῆς εἶναι τὸν ἥλιον, ὥστε τῶν Φωκέων τοῖς ἔχουσιν ἐπὶ τῇ ἀτραπῷ τὴν φρουρὰν οὐ πρότερον ἐπιόντες οἱ βάρβαροι παρέσχοντο αἴσθησιν πρὶν ἢ πλησίον ἐγεγόνεσαν. ἐνταῦθα δὲ οἱ μὲν μάχης ἦρχον, οἱ δὲ ἠμύνοντο ἐρρωμένως, τέλος δὲ ἐβιάσθησαν καὶ ἀναχωροῦσιν ἀπὸ τῆς ἀτραποῦ· καταδραμόντες μέντοι παρὰ τοὺς συμμάχους καὶ ἀπαγγείλαντες τὰ παρόντα ἔφθησαν πρὶν ἢ ἀκριβῆ καὶ πανταχόθεν τελέαν γενέσθαι τοῦ Ἑλληνικοῦ τὴν κύκλωσιν.
And so it happened on that day that a dense mist settled upon the mountain and caused the sun to be dimmed; as a result, the Phocians guarding the path did not perceive the advancing barbarians until they were already near at hand. At this point, some of the enemy began an attack, whereas the Phocians bravely defended themselves, but in the end they were overwhelmed and withdrew from the path. Nevertheless, running down quickly to their allies, they were able to report the events just before the encirclement of the Greeks became complete and fully secured on all sides.