Bhagavad Gita 18.49
He whose mind is entirely detached, who has conquered himself, and whose desires have vanished, reaches that stage of perfect freedom through his renunciation, where action completes itself and leaves no seed.
असक्तबुद्धिः सर्वत्र जितात्मा विगतस्पृहः।नैष्कर्म्यसिद्धिं परमां संन्यासेनाधिगच्छति॥asaktabuddhiḥ sarvatra jitātmā vigataspṛhaḥ|naiṣkarmyasiddhiṃ paramāṃ saṃnyāsenādhigacchati||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).