τῆς ὁδοῦ ἁμαρτάνειν

From LSJ

ὃν οὐ τύπτει λόγος οὐδὲ ῥάβδος → if words don't get through, neither a beating will | if the carrot doesn't work, the stick will not work either | whom words do not strike, neither does the rod

Source

Greek > English (Woodhouse)

lose one's way