Passage 4.14.8
Μεσσήνιοι γὰρ οὐκ ἐσποιοῦσιν Ἀριστομένην Ἡρακλεῖ παῖδα ἢ Διί, ὥσπερ Ἀλέξανδρον Ἄμμωνι οἱ Μακεδόνες καὶ Ἄρατον Ἀσκληπιῷ Σικυώνιοι· Ἀριστομένει δὲ πατέρα Ἑλλήνων μὲν οἱ πολλοὶ Πύρρον φασὶν εἶναι, Μεσσηνίους δὲ οἶδα αὐτὸς ἐπὶ ταῖς σπονδαῖς Ἀριστομένην Νικομήδους καλοῦντας. οὗτος μὲν οὖν ἀκμάζων ἡλικίᾳ καὶ τόλμῃ καὶ ἄλλοι τῶν ἐν τέλει παρώξυνον ἐπὶ τὴν ἀπόστασιν· ἐπράσσετο δὲ ταῦτα οὐκ εὐθὺς ἐκ τοῦ φανεροῦ, κρύφα δὲ ἐς Ἄργος καὶ παρὰ τοὺς Ἀρκάδας ἀπέστελλον, εἴ σφισιν ἀπροφασίστως καὶ μηδὲν ἐνδεεστέρως ἢ ἐπὶ τοῦ πολέμου τοῦ προτέρου ἀμῦναι θελήσουσιν.
For the Messenians do not claim Aristomenes as the son of Heracles or Zeus, as the Macedonians say Alexander was the son of Ammon, or as the Sicyonians assert Aratus was the son of Asclepius. Instead, most of the Greeks say that Aristomenes' father was Pyrrhus, but I myself know that the Messenians, when making oaths, call Aristomenes the son of Nicomedes. At that time Aristomenes, in the prime of his strength and daring, and other leading men stirred them up into revolt. These events did not immediately occur openly; rather, secret embassies were sent to Argos and among the Arcadians, asking whether these peoples would readily and no less eagerly than in the former war wish to come to their defense.