Passage 8.27.10
τηνικαῦτα οἱ Λακεδαιμόνιοι προθυμίας μὲν οὖν ἕνεκα Ἀρκάδας τε ἂν τοὺς ἄλλους καὶ τοὺς Μεγαλοπολίτας ἐποίησαν ἀναστάτους, ἀμυνομένων δὲ τῶν τότε οὐκ ἀθύμως καὶ ἅμα τῶν περιοίκων ἀπροφασίστως σφίσιν ἐπικουρούντων, λόγου μὲν συνέπεσεν οὐδὲν ἄξιον γενέσθαι παρὰ οὐδετέρων· Φίλιππον δὲ τὸν Ἀμύντου καὶ Μακεδόνων τὴν ἀρχὴν οὐχ ἥκιστα αὐξηθῆναι τὸ ἔχθος τὸ Ἀρκάδων ἐς Λακεδαιμονίους ἐποίησε, καὶ Ἕλλησιν ἐν Χαιρωνείᾳ καὶ αὖθις περὶ Θεσσαλίαν τοῦ ἀγῶνος οὐ μετέσχον οἱ Ἀρκάδες.
At that time, the Lacedaemonians, through sheer eagerness, would have made homeless both the other Arcadians and particularly those of Megalopolis. But since the Arcadians then resisted courageously and the neighboring peoples, without hesitation, came to their aid, neither side achieved anything worthy of mention. However, this hostility of the Arcadians toward the Lacedaemonians most notably increased the power of Philip son of Amyntas and of the Macedonians, with the result that the Arcadians took no part in the struggle of the Greeks either at Chaeronea or subsequently around Thessaly.