Bhagavad Gita 6.3
आरुरुक्षोर्मुनेर्योगं कर्म कारणमुच्यते। योगारूढस्य तस्यैव शमः कारणमुच्यते।।6.3।।
ārurukṣormuneryogaṃ karma kāraṇamucyate| yogārūḍhasya tasyaiva śamaḥ kāraṇamucyate||6.3||
arurukshormuneryogam karma karanamucyate yogarudhasya tasyaiva shamah karanamucyate6.3
Meaning
For a sage who wishes to ascend to yoga, action is the means. For one who has already attained yoga, serenity and cessation of activity become the means. The path evolves as the seeker grows.
योग में आरूढ़ होने की इच्छा वाले मुनि के लिए कर्म करना ही हेतु (साधन) कहा है और योगारूढ़ हो जाने पर उसी पुरुष के लिए शम को (शांति, संकल्पसंन्यास) साधन कहा गया है।
This is verse 3 of 47 in Chapter 6 (Dhyana Yoga) of the Bhagavad Gita.