διδάσκειν ἃ πονηρῶς ἔχει τῶν πραγμάτων
From LSJ
διὸ δὴ πᾶς ἀνὴρ σπουδαῖος τῶν ὄντων σπουδαίων πέρι πολλοῦ δεῖ μὴ γράψας ποτὲ ἐν ἀνθρώποις εἰς φθόνον καὶ ἀπορίαν καταβαλεῖ → And this is the reason why every serious man in dealing with really serious subjects carefully avoids writing, lest thereby he may possibly cast them as a prey to the envy and stupidity of the public | Therefore every man of worth, when dealing with matters of worth, will be far from exposing them to ill feeling and misunderstanding among men by committing them to writing
