ἢ δεῖ σιωπᾶν ἢ λέγειν τὰ καίρια → you should either keep silence or make timely remarks (Menander)
ἐφ' ᾧτε, i. e. ἐπὶ τούτῳ ὥστε, v. ἐπί B. 111.3.