Bhagavad Gita Verse 2.47

तेरा कर्म करने में ही अधिकार है, उसके फलों में कभी नहीं। इसलिए तू कर्मों के फल हेतु मत हो तथा तेरी कर्म न करने में भी आसक्ति न हो|

O ARJUNA, always remember what I am about to say to you for it is the law of KARMA, a law that one should always obey in life should he/she ever feel resentment, frustration, anxiety, or grief:You have the right only to perform your actions, duties and responsibilities in life; however, the results of these actions should not concern you at all. You should not even desire results for your actions because the results are simply not in your hands, but in the hands of the Lord. Neither should you lean towards inaction. (This is the most important shloka describing Karmyoga.)