These sayings come from the Gnomologium Vaticanum
58 “When Aristotle was asked what the most burdensome thing in life is he said “staying silent.”
῾Ο αὐτὸς ἐρωτηθείς, τί δυσκολώτατόν ἐστιν ἐν βίῳ, εἶπε· „τὸ σιωπᾶν”.
547 “Philoxenos said that peoples’ ears get worn out by a tongue for they are eager to tell people what they don’t know before listening well.”
Φιλόξενος ἔφησε τῶν ἀνθρώπων τὰς ἀκοὰς τῇ γλώσσῃ συντετρῆσθαι· πρὶν γὰρ ἢ καλῶς ἀκοῦσαι, σπουδάζειν αὐτοὺς ἅπερ οὐκ ἐπίστανται πρὸς ἄλλους λέγειν.
456 “Pittakos asked Bias “what is hardest in life?” And when he answered “to know yourself”, he asked again, “what is easiest?” And Bias said in response “to criticize someone else.”
῾Ο αὐτὸς Βίαντα ἠρώτησε· „τί δυσχερέστερον ἐν τῷ βίῳ”; τοῦ δὲ εἰπόντος· „τὸ ἑαυτὸν γνῶναι” πάλιν ἤρετο· „τί δὲ ῥᾴδιον”; καὶ πάλιν Βίας φησί· „τὸ ἕτερον ψέξαι”.
382 “[Kratês] the Cynic used to say that it is better to slip with your foot than your tongue.”
῾Ο αὐτὸς ἔφη κρεῖττον εἶναι τῷ ποδὶ ὀλισθῆσαι ἢ τῇ γλώττῃ.
219 “When Demosthenes was asked what kind of thing is the greatest weapon, he said “speech”.
῾Ο αὐτὸς ἐρωτηθεὶς ποῖον μέγιστον ὅπλον εἶπε· „λόγος”.