Bhagavad Gita Chapter 6 Verse 3
भगवद् गीता अध्याय 6 श्लोक 3

आरुरुक्षोर्मुनेर्योगं कर्म कारणमुच्यते।
योगारूढस्य तस्यैव शमः कारणमुच्यते।।6.3।।



English Translation - Swami Sivananda
6.3 For a sage who wishes to attain to Yoga, action is said to be the means; for the same sage who has attained to Yoga, inaction (iescence) is said to be the means.


English Translation of Sanskrit Commentary By Sri Shankaracharya's
6.3 Aruruksoh, for one who wishes to ascend, who has not ascended, i.e. for that very person who is unable to remain established in Dhyana-yoga;-for which person who is desirous to ascend?-munch, for the sage, i.e. for one who has renounced the results of actions;-trying to ascend to what?-yogam, to (Dhyana-) yoga; karma, action; ucyate, is said to be; the karanam, means. Tasya, for that person, again; yoga-arudhasya, when he has ascended to (Dhyana-) yoga; samah, inaction, withdrawl from all actions; eva, alone; ucyate, is said to be; karanam, the means for remaining poised in the state of meditation. This is the meaning.
To the extent that one withdraws from actions, the mind of that man who is at cease and self-controlled becomes concentrated. When this occurs, he at once becomes established in Yoga. And accordingly has it been said by Vyasa: For a Brahmana there is no wealth conparable to (the knowledge of) oneness, sameness, truthfulness, character, eipoise, harmlessness, straightforwardness and withdrawal from various actions (Mbh. Sa. 175.37).
After that, now is being stated when one becomes established in Yoga:


Transliteration Bhagavad Gita 6.3Aarurukshormuneryogam karma kaaranamuchyate;
Yogaaroodhasya tasyaiva shamah kaaranamuchyate.


Word Meanings Bhagavad Gita 6.3ārurukṣhoḥ—a beginner; muneḥ—of a sage; yogam—Yog; karma—working without attachment; kāraṇam—the cause; uchyate—is said; yoga ārūḍhasya—of those who are elevated in Yog; tasya—their; eva—certainly; śhamaḥ—meditation; kāraṇam—the cause; uchyate—is said