Passage 2.9.5
ἔμελλε δὲ ἄρα καὶ αὐτῷ Φιλίππῳ τὸ ἀνδροφόνον φάρμακον ἔσεσθαι συμφορά· τὸν γάρ οἱ παῖδα Δημήτριον ὁ νεώτερος τῶν Φιλίππου παίδων Περσεὺς φαρμάκῳ διέφθειρε καὶ διʼ αὐτὸ καὶ τῷ πατρὶ ἀθυμήσαντι παρέσχεν αἰτίαν ἀποθανεῖν. παρεδήλωσα δὲ τάδε ἀπιδὼν ἐς τὸ Ἡσιόδου σὺν θεῷ πεποιημένον, τὸν ἐπʼ ἄλλῳ βουλεύοντα ἄδικα ἐς αὑτὸν πρῶτον τρέπειν.
Indeed, the murderous drug was also destined to bring misfortune upon Philip himself. For Perseus, the younger of Philip's sons, destroyed Philip's other son Demetrius with poison, and this act caused their father such grief that it became a reason for his own death. I have cited these things, mindful of Hesiod's divinely inspired words, that whoever plots evil against another man turns it first upon himself.