Passage 6.7.3
οὗτος δὲ ὁ Πεισίροδος καὶ ἐν τῇ Ἄλτει παρὰ τῆς μητρὸς τὸν πατέρα ἕστηκε. Διαγόραν δὲ καὶ ὁμοῦ τοῖς παισὶν Ἀκουσιλάῳ καὶ Δαμαγήτῳ λέγουσιν ἐς Ὀλυμπίαν ἐλθεῖν· νικήσαντες δὲ οἱ νεανίσκοι διὰ τῆς πανηγύρεως τὸν πατέρα ἔφερον βαλλόμενόν τε ὑπὸ τῶν Ἑλλήνων ἄνθεσι καὶ εὐδαίμονα ἐπὶ τοῖς παισὶ καλούμενον. γένος δὲ ὁ Διαγόρας τὸ ἐξ ἀρχῆς Μεσσήνιος πρὸς γυναικῶν ἦν καὶ ἀπὸ τῆς Ἀριστομένους ἐγεγόνει θυγατρός.
This same Peisirodos stands also in the Altis near his father, dedicated there by his mother. They say that Diagoras came to Olympia accompanied by his sons, Akousilaos and Damagetos. After the young men achieved victory, they carried their father through the assembly, and the Greeks showered him with flowers, calling him blessed for his sons' triumph. By descent Diagoras was originally of Messenian stock on his mother's side, being descended from a daughter of Aristomenes.