Passage 4.8.8
ἐμάχοντο δὲ καὶ οἱ βασιλεῖς ἀξίως λόγου, Θεόπομπος δὲ καὶ ἀκρατέστερον ὥρμητο ὡς αὐτὸν ἀποκτενῶν Εὐφαῆ. Εὐφαὴς δὲ ὁρῶν ἐπιόντα εἶπεν ἄρα πρὸς τὸν Ἄντανδρον οὐδὲν εἶναι τὰ Θεοπόμπου διάφορα ἢ ὅσα ὁ πρόγονος αὐτοῦ Πολυνείκης ἐτόλμησε· Πολυνείκην τε γὰρ στρατιὰν ἐπὶ τὴν πατρίδα ἀγαγόντα ἐξ Ἄργους ἀποκτεῖναι τὸν ἀδελφὸν αὐτοχειρὶ καὶ ἀποθανεῖν ὑπὸ ἐκείνου, Θεόπομπόν τε ἐθέλειν ἐς τὸ ἴσον καταστῆσαι μιάσματος τοῖς ἀπὸ Λαΐου καὶ Οἰδίποδος τὸ Ἡρακλειδῶν γένος· οὐ μέντοι χαίροντά γε ἀπὸ τῆς μάχης διακριθήσεσθαι. τοιαῦτα ἐπιλέγων ἀντεπῄει καὶ οὗτος.
The kings fought also with a valor worthy of mention, and Theopompus, engaging with excessive fury, aimed directly at killing Euphaes. Euphaes, seeing him advancing, remarked then to Antander that the conduct of Theopompus differed in nothing from all that his ancestor Polynices had braved; for Polynices had led an army from Argos against his fatherland, had slain his brother by his own hand and himself had perished at his brother’s hand. In the same way, said Euphaes, Theopompus wished to involve in equal pollution with the descendants of Laius and Oedipus the race of the Heracleidae. Nevertheless, Euphaes declared, Theopompus would not return rejoicing from this battle. Thus speaking, he himself went forward to meet him.