ἐπὶ ἓξ ἢ ἕπτα σταδίους οἱ Πλαταιῆς τὴν ἐπὶ τῶν Θηβῶν ἐχώρησαν

From LSJ

ἢ δεῖ σιωπᾶν ἢ λέγειν τὰ καίρια → you should either keep silence or make timely remarks (Menander)

Source