Bhagavad Gita · 18.8

दुःखमित्येव यत्कर्म कायक्लेशभयात्त्यजेत्।स कृत्वा राजसं त्यागं नैव त्यागफलं लभेत्॥

duḥkham ity eva yat karma kāya-kleśha-bhayāt tyajet sa kṛtvā rājasaṁ tyāgaṁ naiva tyāga-phalaṁ labhet

One who gives up action out of fear of bodily discomfort, thinking 'it is painful' — such renunciation is in the mode of passion (rajas) and does not bring the fruit of true renunciation.

— Bhagavad Gita 18.8

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)