Passage 5.27.4
καὶ γὰρ ἐσθέουσιν ἐς τὴν Ἄλτιν ἀπορρηγνύοντες τὰ δεσμὰ ἢ καὶ ἐκφεύγοντες τοὺς ἄγοντας καὶ ἐπιπηδῶσιν αὐτῷ πολλῷ δή τι ἐμμανέστερον ἢ ἐπὶ τὴν καλλίστην ἵππον ζῶσάν τε καὶ ἠθάδα ἀναβαίνεσθαι· ἀπολισθάνουσί τε δὴ αὐτοῖς αἱ ὁπλαὶ καὶ ὅμως οὐκ ἀπαγορεύουσι χρεμετίζοντές τε μᾶλλον καὶ ἐπιπηδῶντες μετὰ βιαιοτέρας τῆς ὁρμῆς, πρὶν ἂν ὑπὸ μαστίγων καὶ ἀνάγκης ἰσχυρᾶς ἀφελκυσθῶσι· πρότερον δὲ οὐκ ἔστιν ἀπαλλαγή σφισιν οὐδεμία ἀπὸ τοῦ χαλκοῦ.
For indeed, they rush into the Altis either breaking their bonds or fleeing from those who lead them, and leap upon it with far greater frenzy than they would mount a living mare, even one most beautiful and gentle. Their hooves slip upon it, yet nevertheless they do not desist, neighing all the louder and springing upon it with more vehement impulse, until finally they are drawn away by lashes and great force; and until that time there is for them no release whatsoever from the bronze.