Plato, Letters 312d

ἐμοῦ δὲ ὄνειδος ἀμφοῖν. περὶ μὲν οὖν τούτων ταῦτα.τὸ δὲ σφαιρίον οὐκ ὀρθῶς ἔχει· δηλώσει δέ σοι Ἀρχέδημος, ἐπειδὰν ἔλθῃ. καὶ δὴ καὶ περὶ τοῦδε, ὃ δὴ τούτου τιμιώτερόν τʼ ἐστὶν καὶ θειότερον, καὶ μάλα σφόδρʼ αὐτῷ δηλωτέον, ὑπὲρ οὗ σὺ πέπομφας ἀπορούμενος. φῂς γὰρ δὴ κατὰ τὸν ἐκείνου λόγον, οὐχ ἱκανῶς ἀποδεδεῖχθαί σοι περὶ τῆς τοῦ πρώτου φύσεως. φραστέον δή σοι διʼ αἰνιγμῶν, ἵνʼ ἄν τι ἡ δέλτος ἢ πόντου ἢ γῆς ἐν πτυχαῖς πάθῃ,

So much, then, about this subject. As to the globe, there is something wrong with it; and Archedemus will point it out to you when he arrives. There is also another matter—much more valuable and divine than the globe—which he most certainly must explain, as you were puzzled about it when you sent him. For, according to his report, you say that you have not had a sufficient demonstration of the doctrine concerning the nature of the First. Now I must expound it to you in a riddling way in order that, should the tablet come to any harm in folds of ocean or of earth, he that readeth may not understand. The matter stands thus: Related to