Passage 10.34.2
Ἐλατεῦσι δὲ ἐξεγένετο μὲν Κάσσανδρον καὶ τὴν Μακεδόνων ἀπώσασθαι στρατιάν, ὑπῆρξε δὲ καὶ Ταξίλου Μιθριδάτῃ στρατηγοῦντος τὸν πόλεμόν σφισιν ἐκφυγεῖν· ἀντὶ τούτου δὲ τοῦ ἔργου Ῥωμαῖοι δεδώκασιν αὐτοῖς ἐλευθέρους ὄντας ἀτελῆ νέμεσθαι τὴν χώραν. ἀμφισβητοῦσι δὲ οὗτοι ξενικοῦ γένους, καὶ Ἀρκάδες φασὶν εἶναι τὸ ἀρχαῖον· Ἔλατον γὰρ τὸν Ἀρκάδος, ἡνίκα ἐπὶ τὸ ἱερὸν Φλεγύαι τὸ ἐν Δελφοῖς ἐστρατεύσαντο, ἀμῦναί τε τῷ θεῷ καὶ ἐν τῇ Φωκίδι ὁμοῦ τῷ στρατεύματι αὐτὸν καταμείναντα Ἐλατείας οἰκιστὴν γενέσθαι.
The people of Elateia managed both to drive out Cassander and his Macedonian army, and later, when Taxilus commanded Mithridates' war against them, they succeeded in escaping disaster. On account of these deeds, the Romans granted them autonomy and exemption from taxation, allowing them to inhabit their territory freely. The origins of the Elateans, however, are disputed, for they claim to be descended from foreign stock. The Arcadians assert that the Elateans originally came from Arcadia, stating that Elatos, the son of Arkas, when the Phlegyans marched upon the sanctuary at Delphi, remained behind in Phocis together with his army to defend the god, and thus became the founder of Elateia.