εκεί το τρίψιμο

listen to the pronunciation of εκεί το τρίψιμο
اليونانية - الإنجليزية
there's the rub
(deyim) (also "Therein lies the rub") Something that you say when you are explaining what the difficulty is in a particular situation
that is the root of the problem, that is the source of the trouble