Passage 9.7.2
δοκεῖ δέ μοι τὰς Θήβας οἰκίσαι ὁ Κάσσανδρος κατὰ ἔχθος Ἀλεξάνδρου μάλιστα· ἐπεξῆλθε δὲ καὶ τὸν πάντα οἶκον Ἀλεξάνδρου φθείρων, ὃς Ὀλυμπιάδα γε παρέβαλε καταλεῦσαι τοῖς ἐπʼ αὐτὴν Μακεδόνων παρωξυσμένοις καὶ τοὺς παῖδας Ἀλεξάνδρου τόν τε ἐκ Βαρσίνης Ἡρακλέα καὶ Ἀλέξανδρον τὸν ἐκ Ῥωξάνης ἀπέκτεινεν ὑπὸ φαρμάκων. οὐ μὴν οὐδὲ αὐτὸς χαίρων τὸν βίον κατέστρεψεν· ἐπλήσθη γὰρ ὑδέρῳ, καὶ ἀπʼ αὐτοῦ ζῶντι ἐγένοντο εὐλαί.
It seems to me that Cassander founded Thebes chiefly because of his hatred toward Alexander. He also carried out the destruction of Alexander's entire family, inciting the Macedonians against Olympias so that they stoned her to death, and murdering Alexander's sons, both Heracles, born from Barsine, and Alexander, the son of Roxane, by poison. Yet Cassander himself did not end his life happily; for he became full of dropsy, and worms arose from his flesh while he was still alive.