φυλακὴν ἔχειν

From LSJ

Ἐλεύθερον φύλαττε τὸν σαυτοῦ τρόπον → Te liberum ipse moribus praesta tuis → Die Freiheit wahre deiner eignen Lebensart

Menander, Monostichoi, 144

Greek > English (Woodhouse)

be on the qui vive, on one's guard