Passage 10.25.8
Λέσχεως δὲ ἐς τὴν Αἴθραν ἐποίησεν, ἡνίκα ἡλίσκετο Ἴλιον, ὑπεξελθοῦσαν ἐς τὸ στρατόπεδον αὐτὴν ἀφικέσθαι τὸ Ἑλλήνων καὶ ὑπὸ τῶν παίδων γνωρισθῆναι τῶν Θησέως, καὶ ὡς παρʼ Ἀγαμέμνονος αἰτήσαι Δημοφῶν αὐτήν· ὁ δὲ ἐκείνῳ μὲν ἐθέλειν χαρίζεσθαι, ποιήσειν δὲ οὐ πρότερον ἔφη πρὶν Ἑλένην πεῖσαι· ἀποστείλαντι δὲ αὐτῷ κήρυκα ἔδωκεν Ἑλένη τὴν χάριν. ἔοικεν οὖν ὁ Εὐρυβάτης ὁ ἐν τῇ γραφῇ ἀφῖχθαί τε ὡς τὴν Ἑλένην τῆς Αἴθρας ἕνεκα καὶ τὰ ἐντεταλμένα ὑπὸ τοῦ Ἀγαμέμνονος ἀπαγγέλλειν.
But Lescheos depicted Aethra, at the moment Troy was being captured, slipping away and reaching the Greek encampment, where she was recognized by the sons of Theseus. He showed how Demophon asked Agamemnon for her, and how Agamemnon indicated he wished to grant Demophon this favor, yet stated he would not do so before securing Helen's consent. Accordingly, he sent a herald to Helen, and she granted the request. Thus, Eurybates, as portrayed in the painting, seems to have come to Helen on account of Aethra, declaring the instructions which Agamemnon had given him.