Passage 3.7.7
Ἀρίστωνι δὲ τῷ Ἀγησικλέους ἀγαγομένῳ γυναῖκα ἥντινα παρθένον μὲν τῶν ἐν Λακεδαίμονι εἶναί φασιν αἰσχίστην, γυναικῶν δὲ τὸ εἶδος καλλίστην ὑπὸ Ἑλένης γενέσθαι, ταύτην ἀγαγομένῳ τῷ Ἀρίστωνι ἐγένετο υἱὸς Δημάρατος ἐν μόνοις μησὶν ἑπτά· καὶ αὐτῷ μετὰ τῶν ἐφόρων καθημένῳ τηνικαῦτα ἐν βουλῇ ἦλθεν οἰκέτης ἀπαγγέλλων τετέχθαι οἱ παῖδα. Ἀρίστων δὲ ἐπῶν τῶν ἐν Ἰλιάδι ἐς τὴν Εὐρυσθέως γένεσιν πεποιημένος λήθην ἢ μηδὲ ἀρχὴν συνεὶς αὐτῶν οὐκ ἔφη τῶν μηνῶν ἕνεκα αὑτοῦ τὸν παῖδα εἶναι.
To Ariston son of Agesikles was married a woman who, it is said, among the maidens of Sparta was the most repulsive, yet who became the most beautiful of all women through the intervention of Helen. To this woman, after having been wedded to Ariston, was born a son, Demaratos, after only seven months. As Ariston was sitting at the time with the ephors in council, a servant arrived, bringing the news that a child had been born to him. Ariston, either forgetting the passage in the Iliad regarding the birth of Eurystheus or never having understood it at all, declared that this child could not possibly be his own because of the short duration of the months.