Aelian, Historical Miscellanies 13.7
ὅτε εἷλε τὴν Θηβαίων πόλιν Ἀλέξανδρος, ἀπέδοτο τοὺς ἐλευθέρους πάντας πλὴν ἱερέων. ἀφῆκε δὲ τῆς πράσεως καὶ τοὺς τοῦ πατρὸς ξένους (ὡμήρευσε γὰρ παρ᾽ αὐτοῖς ὁ Φίλιππος ἔτι παῖς ὢν) καὶ τοὺς συγγενεῖς δὲ τούτων ἀφῆκεν. ἐτίμησε δὲ καὶ τοὺς ἐγγόνους τοὺς τοῦ Πινδάρου, καὶ τὴν οἰκίαν αὐτοῦ μόνην εἴασεν ἑστάναι.
When Alexander took the city of the Thebans, he sold as slaves all the free-men except the priests. He also exempted from being sold the guest-friends of his father (for Philip as a child was taken as a hostage by them) and he set free their relatives. He also honoured the descendants of Pindar, and he allowed his house only to stand.