Arrian, Anabasis 2.15
But as for the Greek envoys who had reached Darius before the battle. When he learned that these also were captured, he ordered them to send to him. They were Euthycles the Spartiate, Thessaliscus son of Ismenius, and Dionysidorus, Olympian victor, of Thebes; and Iphicrates son of Iphicrates the general, of Athens. When these envoys reached Alexander, he at once dismissed Thessaliscus and Dionysidorus, Thebans though they were, partly from compassion for Thebes and partly because it seemed that they had acted pardonably, since their city had been enslaved by Macedonians, had they were looking for what help they could get for themselves and for their country too from Dareius and Persia; Alexander therefore took a kindly view of the doing of both; but privately he said he released Thessaliscus from regard for his family – since he was one of the Theban nobles – and Dionysidorus because of his athletic victory at Olympia.