यदा हि नेन्द्रियार्थेषु न कर्मस्वनुषज्जते | सर्वसङ्कल्पसंन्यासी योगारूढस्तदोच्यते ||६-४||
yadā hi nendriyārtheṣu na karmasvanuṣajjate . sarvasaṅkalpasaṃnyāsī yogārūḍhastadocyate ||6-4||
6.4. When, a person indulges himself neither in what is desired by the senses nor in the actions [for it], then [alone], being a man renouncing all intentions, he is said to have mounted on the Yoga.
Shri Purohit Swami
6.4 When a man renounces even the thought of initiating action, when he is not interested in sense objects or any results which may flow from his acts, then in truth he understands spirituality.
Sri Abhinav Gupta
6.4 Yada etc. What is desired by the senses : Objects of senses. The actions for them : actions such as earning the objects and so on. In this [path of] knowledge one should be necessarily attentive. This [the Lord] says-
6.4 When this Yogin, because of his natural disposition to the experience of the self, loses attachment, i.e., gets detached from sense-objects, i.e., things other than the self, and actions associated with them - then he has abandoned all desires and is said to have climbed the heights of Yoga. Therefore, for one wishing to climb to Yoga, but is still disposed to the experience of the sense-objects, Karma Yoga consisting of the practice of detachment to these objects, becomes the cause for success in Yoga. Therefore one who wishes to climb to Yoga must perform Karma Yoga consisting in the practice of detachment from sense-objects.
Sri Krsna further elucidates the same:
6.4 Hi, verily; yada, when; a yogi who is concentrating his mind, sarva-sankalpa-sannyasi, who has given up thought about everything-who is apt to give up (sannyasa) all (sarva) thoughts (sankalpa) which are the causes of desire, for things here and hereafter; na anusajjate, does not become attached, i.e. does not hold the idea that they have to be done by him; indriya-arthesu, with regard to sense-objects like sound etc.; and karmasu, with regard to actions-nitya, naimittika, kamya and nisiddha (prohibited) because of the absence of the idea of their utility; tada, then, at that time; ucyate, he is said to be; yoga-arudhah, established in Yoga, i.e. he is said to have attained to Yoga. From the expression, ‘one who has given up thought about eveything’, it follows that one has to renounce all desires and all actions, for all desires have thoughts as their source. This accords with such Smrti texts as: ‘Verily, desire has thought as its source. Sacrifices arise from thoughts’ (Ma. Sm. 2.3); ‘O Desire, I know your source. You surely spring from thought. I shall not think of you. So you will not arise in me’ (Mbh. Sa. 177.25). And when one gives up all desires, renunciation of all actions becomes accomplished. This agrees with such Upanisadic texts as, ‘(This self is identified with desire alone.) What it desires, it resolves; what it resolves, it works out’ (Br. 4.4.5); and also such Smrti texts as, ‘Whatever actions a man does, all that is the effect of desire itself’ (Ma. Sm. 2.4). It accords with reason also. For, when all thoughts are renounced, no one can even move a little. So, by the expression, ‘one who has given up thought about everything’, the Lord makes one renounced all desires and all actions. When one is thus established in Yoga, then by that very fact one’s self becomes uplifted by oneself from the worldly state which is replete with evils. Hence,
6.4 For, when one loses attachment for the things of the senses and to actions, then has the abandoned all desires and is said to have climbed the heights of Yoga.
6.4 Verily, [Verily: This word emphasizes the fact that, since attachment to sense objects like sound etc. and to actions is an obstacle in the path of Yoga, therefore the removal of that obstruction is the means to its attainment.] when a man who has given up thought about everything does not get attached to sense-objects or acitons, he is then said to be established in Yoga.
6.4 When a man is not attached to the sense-objects or to actions, having renounced all thoughts, then he is said to have attained to Yoga.
6.4 यदा when? हि verily? न not? इन्द्रयार्थेषु in senseobjects? न not? कर्मसु in actions? अनुषज्जते is attached? सर्वसङ्कल्पसंन्यासी renouncer of all thoughts? योगारूढः one who has attained to Yoga? तदा then? उच्यते is said.Commentary Yogarudha he who is enthroned or established in Yoga. When a Yogi? by keeping the mind ite steady? by withdrawing it from the objects of the senses? has attachment neither for sensual objects such as sound? nor for the actions (Karmas? Cf. notes to V.13)? knowing that they are of no use to him when he has renounced all thoughts which generate various sorts of desires for the objects of this world and of the next? then he is said to have become a Yogarudha.Do not think of senseobjects. The desires will die by themselves. How can you free yourself from thinking of the objects Think of God or the Self. Then you can avoid thinking of the objects. Then you can free yourself from thinking of the objects of the senses.Renunciation of thoughts implies that all desires and all actions should be renounced? because all desires are born of thoughts. You think first and then act (strive) afterwards to possess the objects of your desire for enjoyment.Whatever a man desires? that he willsAnd whatever he wills? that he does. – Brihadaranyaka Upanishad? 4.4.5Renunciation of all actions necessarily follows from the renunciation of all desires.O desire I know where thy root lies. Thou art born of Sankalpa (thought). I will not think of thee and thou shalt cease to exist along with the root. – Mahabharata? Santi Parva? 177.25Indeed desire is born of thought (Sankalpa)? and of thought? Yajnas are born. – Manu Smriti? II.2