Bhagavad Gita 3.30

मयि सर्वाणि कर्माणि संन्यस्याध्यात्मचेतसा |
निराशिर्निर्ममो भूत्वा युध्यस्व विगतज्वर:

Translation

Performing all works as an offering unto Me, constantly meditate on Me as the Supreme. Become free from desire and selfishness, and with your mental grief departed, fight!