Plato, Letters 319c

καὶ μάλα πλαστῶς γελῶν, εἰ μέμνημαι, ὡς παιδευθέντα με ἐκέλευες ποιεῖν πάντα ταῦτα ἢ μὴ ποιεῖν. ἔφην ἐγὼ κάλλιστα μνημονεῦσαί σε. οὐκοῦν παιδευθέντα, ἔφησθα, γεωμετρεῖν, ἢ πῶς; κἀγὼ τὸ μετὰ ταῦτα ὃ ἐπῄει μοι εἰπεῖν οὐκ εἶπον, φοβούμενος μὴ σμικροῦ ῥήματος ἕνεκα τὸν ἔκπλουν ὃν προσεδόκων, μή μοι στενὸς γίγνοιτο ἀντʼ εὐρυχωρίας. ἀλλʼ οὖν ὧν ἕνεκα πάντʼ εἴρηται ταῦτʼ ἐστί· μή με διάβαλλε λέγων ὡς οὐκ εἴων ἐγώ σε πόλεις Ἑλληνίδας ἐρρούσας

if my memory serves me—You bade me be educated before I did all these things or else not do them. I replied that your memory was excellent. You then said—Did you mean educated in land-measuring or what? But I refrained from making the retort which it occurred to me to make, for I was alarmed about the homeward voyage I was hoping for, lest instead of having an open road I should find it shut, and all because of a short saying. Well then, the purpose of all I have said is this: do not slander me by declaring that I was hindering you from colonizing the Greek cities that were ruined by the barbarians,