yadā hi nendriyārtheṣu
na karmasv anuṣajjate
sarva-sańkalpa-sannyāsī
yogārūḍhas tadocyate

Translation of Bhagavad Gita 6.4

A person is said to be elevated in yoga when, having renounced all material desires, he neither acts for sense gratification nor engages in fruitive activities.

Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:

When a person is fully engaged in the transcendental loving service of the Lord, he is pleased in himself, and thus he is no longer engaged in sense gratification or in fruitive activities. Otherwise, one must be engaged in sense gratification, since one cannot live without engagement. Without Krishna consciousness, one must be always seeking self-centered or extended selfish activities. But a Krishna conscious person can do everything for the satisfaction of Krishna and thereby be perfectly detached from sense gratification. One who has no such realization must mechanically try to escape material desires before being elevated to the top rung of the yoga ladder.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

This verse speaks of the characteristics of the person who has attained   steady meditation (yogarudhah), one who has a completely pure heart. He is not attached either to the sense objects such as sound, nor to actions for attaining enjoyment of the objects of the senses (karmasu).

Commentary by Sri Ramanuja of Sri Sampradaya:

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:

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

What qualifies a person to be qualified for sannyasa or renunciation in abnegation for whom cessation of activities is prescribed? Lord Krishna explains that when one is no longer enamoured by the pleasures of the senses and the sense objects and is also not even attracted to performing the actions which are the means to obtain them, such a person is qualified for dhyana yoga or the science of the individual consciousness attaining communion with the ultimate consciousness by mediation. This is because one must develop the renunciation habitually until the dross of desires is eradicated along with not the slightest inclination to perform any activity that will lead to enjoyment of sense objects and the opportunity for sense gratification completely neutralising all desires. Then a person is known to be have factually attained dhyana yoga.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

In this verse Lord Krishna tells the signs of one who has established themselves in equanimity of mind. For such a person there is absolute detachment because there is no desire for results. If one is devoted to the Supreme Lord then all imperfections dissolved on their own. If one is not devoted then they are eradicated by special effort.

Now begins the summation.

How does one become detached from one’s actions? The answer is to renounce the desire for the rewards of actions or if one is devoted to the Supreme Lord to offer all the rewards to Him. By acting in either of these ways one is considered performing renunciation for the Supreme Lord.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

If one wants to understand exactly when performing karma yoga or prescribed Vedic activities transforms itself to the heights of dhyana yoga or the science of the individual soul attaining communion with the ultimate soul by meditation is now revealed. Lord Krishna speaks the words: na karmasi anusajjate meaning when one no longer craves or is inclined to make any effort for sense objects. Such a person thinks why should I strive to obtain pleasures which are here today and gone tomorrow being only temporary? Then with constant endeavour one ceases to look for opportunities to facilitate favourable circumstances to enjoy sensual pleasures and evenually evaporates all thoughts of enjoying sense objects along with dissolving the memories of previous enjoyments. Only such a being is considered to be firmly established in yoga or the science of the individual soul attaining communion with the ultimate consciousness.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

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,

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

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-

Sanskrit Shloka Without Transliteration Marks:

yada hi nendriyarthesu
na karmasv anusajjate
sarva-sankalpa-sannyasi
yogarudhas tadocyate

Sanskrit to English Word for Word Meanings:

yadā — when; hi — certainly; na — not; indriya-artheṣu — in sense gratification; na — never; karmasu — in fruitive activities; anuṣajjate — one necessarily engages; sarva-sańkalpa — of all material desires; sannyāsī — renouncer; yoga-ārūḍhaḥ — elevated in yoga; tadā — at that time; ucyate — is said to be.