Arrian, Anabasis 1.9.9-10
τοῖς δὲ μετασχοῦσι τοῦ ἔργου ξυμμάχοις, οἷς δὴ καὶ ἐπέτρεψεν Ἀλέξανδρος τὰ κατὰ τὰς Θήβας διαθεῖναι, τὴν μὲν Καδμείαν φρουρᾶι κατέχειν ἔδοξε, τὴν πόλιν δὲ κατασκάψαι ἐς ἔδαφος καὶ τὴν χώραν κατανεῖμαι τοῖς ξυμμάχοις, ὅση μὴ ἱερὰ αὐτῆς· παῖδας δὲ καὶ γυναῖκας καὶ ὅσοι ὑπελείποντο Θηβαίων, πλὴν τῶν ἱερέων τε καὶ ἱερειῶν καὶ ὅσοι ξένοι Φιλίππου ἢ Ἀλεξάνδρου ἢ ὅσοι πρόξενοι Μακεδόνων ἐγένοντο, ἀνδραποδίσαι. καὶ τὴν Πινδάρου δὲ τοῦ ποιητοῦ οἰκίαν καὶ τοὺς ἀπογόνους τοῦ Πινδάρου λέγουσιν ὅτι διεφύλαξεν Ἀλέξανδρος αἰδοῖ τῆι Πινδάρου.
It seemed best to those allies taking part in the action, whom Alexander entrusted the arrangement of the Theban campaign, to seize the Cadmea with a garrison, but to raze utterly the city to the ground and to distribute to the allies the land around, except for its sacred areas. The children, women, and those who were left of the Thebans, except the priestesses and the priests, and the guest-friends of Philip or Alexander or those who were representatives of the Macedons, were to be enslaved. They say that Alexander spared the house of the poet and his descendants out of respect for Pindar.