आरुरुक्षोर्मुनेर्योगं कर्म कारणमुच्यते। योगारूढस्य तस्यैव शमः कारणमुच्यते ॥

ārurukṣhor muner yogaṁ karma kāraṇam uchyate yogārūḍhasya tasyaiva śhamaḥ kāraṇam uchyate

For a Sage who is seeking Yoga, action is called the means; for the same Sage, when he is enthroned in yoga, serenity is called the means.

In plain words: Krishna says that for someone just starting on the path of yoga, doing good work is the way forward. Once they are settled in yoga, staying calm and peaceful becomes the way forward.