Herodotus, Histories 9.16
After dinner when they were drinking together, the Persian next to him asked [Thersander] in Greek what country was his and Thersander said Orkhomenos. Then he responded “Since you are my dinner companion and have had a drink with me I want to leave a memorial of my belief so that you may understand and be able to make some advantageous plans.
Do you see these Persians dining and the army we left in camp by the river? In a short time you will see that few of these men remain.” The Persian stopped saying these things and cried a lot.
After he was surprised at this confession, he responded, “Isn’t it right to tell these things to Mardonios and those noble Persians around him?”
Then he responded, “Friend, whatever a god decrees is impossible for humans to change: for they say that no one wants to believe what is true. Many of us Persians know this and follow because we are bound by necessity. This is most hateful pain for human beings: when someone knows a lot but has no power.”
I heard these things from Thersander of Orkhomnos and he also told me that he said them to people before the battle occurred at Plataea.”
2] ὡς δὲ ἀπὸ δείπνου ἦσαν, διαπινόντων τὸν Πέρσην τὸν ὁμόκλινον Ἑλλάδα γλῶσσαν ἱέντα εἰρέσθαι αὐτὸν ὁποδαπός ἐστι, αὐτὸς δὲ ὑποκρίνασθαι ὡς εἴη Ὀρχομένιος. τὸν δὲ εἰπεῖν ‘ἐπεὶ νῦν ὁμοτράπεζός τέ μοι καὶ ὁμόσπονδος ἐγένεο, μνημόσυνά τοι γνώμης τῆς ἐμῆς καταλιπέσθαι θέλω, ἵνα καὶ προειδὼς αὐτὸς περὶ σεωυτοῦ βουλεύεσθαι ἔχῃς τὰ συμφέροντα. ’
‘  ὁρᾷς τούτους τοὺς δαινυμένους Πέρσας καὶ τὸν στρατὸν τὸν ἐλίπομεν ἐπὶ τῷ ποταμῷ στρατοπεδευόμενον: τούτων πάντων ὄψεαι ὀλίγου τινὸς χρόνου διελθόντος ὀλίγους τινὰς τοὺς περιγενομένους.’ ταῦτα ἅμα τε τὸν Πέρσην λέγειν καὶ μετιέναι πολλὰ τῶν δακρύων.
 αὐτὸς δὲ θωμάσας τὸν λόγον εἰπεῖν πρὸς αὐτὸν ‘οὐκῶν Μαρδονίῳ τε ταῦτα χρεόν ἐστι λέγειν καὶ τοῖσι μετ᾽ ἐκεῖνον ἐν αἴνῃ ἐοῦσι Περσέων;’ τὸν δὲ μετὰ ταῦτα εἰπεῖν ‘ξεῖνε, ὅ τι δεῖ γενέσθαι ἐκ τοῦ θεοῦ ἀμήχανον ἀποτρέψαι ἀνθρώπῳ: οὐδὲ γὰρ πιστὰ λέγουσι ἐθέλει πείθεσθαι οὐδείς. ’
‘  ταῦτα δὲ Περσέων συχνοὶ ἐπιστάμενοι ἑπόμεθα ἀναγκαίῃ ἐνδεδεμένοι, ἐχθίστη δὲ ὀδύνη ἐστὶ τῶν ἐν ἀνθρώποισι αὕτη, πολλὰ φρονέοντα μηδενὸς κρατέειν.’ ταῦτα μὲν Ὀρχομενίου Θερσάνδρου ἤκουον, καὶ τάδε πρὸς τούτοισι, ὡς αὐτὸς αὐτίκα λέγοι ταῦτα πρὸς ἀνθρώπους πρότερον ἢ γενέσθαι ἐν Πλαταιῇσι τὴν μάχην.