कर्मण्येवाधिकारस्ते मा फलेषु कदाचन ।
मा कर्मफलहेतुर्भिः मा ते सङ्गोस्त्व कर्मणि ॥

Meaning:
You have right over your respective duty only, but no control or claim over the results. The fruits of work should not be your motive. You should never be inactive.

Word meanings:
कर्मण्येवाधिकारस्ते = Your right is only for doing your duty;
मा = do not;
फलेषु = in or among the fruits;
कदाचन = some time or other; once,;
मा = do not;
कर्मफलहेतुर्भिः = fruits of work as a motive;
कर्म = duty or work;
फल = fruit;
हेतू = motive;
मा = do not;
ते = to you or your (here:poss.);
अकर्मणि = without the action or duty;