asakta-buddhiḥ sarvatra
jitātmā vigata-spṛhaḥ
naiṣkarmya-siddhiḿ paramāḿ
sannyāsenādhigacchati

Translation of Bhagavad Gita 18.49

One who is self-controlled and unattached and who disregards all material enjoyments can obtain, by practice of renunciation, the highest perfect stage of freedom from reaction.

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

Real renunciation means that one should always think himself part and parcel of the Supreme Lord and therefore think that he has no right to enjoy the results of his work. Since he is part and parcel of the Supreme Lord, the results of his work must be enjoyed by the Supreme Lord. This is actually Krishna consciousness. The person acting in Krishna consciousness is really a sannyasi, one in the renounced order of life. By such a mentality, one is satisfied because he is actually acting for the Supreme. Thus he is not attached to anything material; he becomes accustomed to not taking pleasure in anything beyond the transcendental happiness derived from the service of the Lord. A sannyasi is supposed to be free from the reactions of his past activities, but a person who is in Krishna consciousness automatically attains this perfection without even accepting the so-called order of renunciation. This state of mind is called yogarudha, or the perfectional stage of yoga. As confirmed in the Third Chapter, yas tv atma-ratir eva syat: one who is satisfied in himself has no fear of any kind of reaction from his activity.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

The first type of sannyasl gives up the faults in his work, characterized by attachment to being the doer and attachment to the results. When that sannyasl perfects his sadhana over time, then he reaches the yogarudha stage. Then he gives up actions completely. That is the second type of sannyasa, mentioned here.

He whose intelligence is free from all attachments to material objects (asakta buddhih), whose mind is under control (jitatma), who has no desire for happiness even of Brahmaloka (vigata sprhah), then, by complete renunciation of all activities (samnyasena), attains the highest perfection of no action at all (naiskarmyam). In other words, at the stage of yogarudha (no actions), with attainment of naiskarmyam, one reaches the highest perfection.

Commentary by Sri Ramanuja of Sri Sampradaya:

18.49 He whose understanding is, on all sides, without attachments, concerning fruits etc., whose ‘self is conquered,’ i.e., who has conquered his mind; who, by contemplating on the agency of the Supreme Person, is free from the habit of attributing agency to the self; and who is thus equipped with Sannyasa which has been positively determined to be the same as Tyaga — such a man, performing actions, attains supreme perfection which is free from all activities. The meaning is that he attains devotion to Dhyana which is the consummation of even Jnana Yoga; he attains Dhyana Yoga (Yoga of meditation) consisting in the complete cessation of sensory activity, which is going to be described hereafter.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

Anticipating that the question may arise of how it is practically possible to accept only the positive and reject the negative, Lord Krishna responds by stating that one whose mentality is unfettered to anything mundane and material, devoid of attachment. Whose mind has conquered the false lure of desires and attraction to the objects of the senses. Who is bereft of egotism and is renounced and situated fully in sattva guna the mode of goodness; such a one achieves no reaction to actions, purity of mind and hence absence of activities. Although such a one may perform actions in actuality it is non-action because there is no conception as the doer. Chapter five verse 8 has already stated: That one who knows the absolute truth understands that they factually are not the doer and verse 13 states: The self controlled being who renounces all actions in their mind remains tranquil and serene and is considered to be topmost.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Perfection in renunciation entails relinquishing all desires for rewards thereof which is perfect equanimity. Perfection in renunciation of actions is abandoning all actions not connected to the Supreme Lord Krishna.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

Perfection in the form of absolute knowledge is performing propitiation unto the Supreme Lord Krishna or any of His authorised incarnations and expansions as ordained in Vedic scriptures in accordance to ones’s own natural propensity. Now He presents the resultant rewards with the words: One whose mind is unfettered and free from attachment to anything, whose senses are totally subdued and completely under control, whose desires and cravings have all evaporated and cease to exist; such a one can reach the Supreme state of perfection. This Supreme state is the highest devotion and is flowing and constant like the purifying flow of the celestial river Ganges, in the form of constant meditation and continuous remembrance of the divine form, divine qualities, divine sweetness and divine pastimes of the effulgent Supreme Lord.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

18.49 Asakta-buddhih, he whose intellect, the internal organ, remains unattached; sarvatra, to everything, with regard to son, wife and others who are the cuases of attachment; jitatma, who has conquered his internal organs; and vigata-sprhah, who is desireless, whose thirst for his body, life and objects of enjoyment have been eradicated;-he who is such a knower of the Self, adhigaccahti, attains; sannyasena, through monasticism, through perfect knowledge or through renunciation of all actions preceded by this knowledge; the paramam, supreme, most excellent; naiskarmya-siddhim, perfection consisting in the state of one free from duties. One is said to be free from duties from whom duties have daparted as a result of realizing that the actionless Brahman is his Self; his state is naiskarmyam. That siddhi (perfection) which is this naiskarmya is naiskarmya-siddhi. Or, this phrase means ‘achievement of naiskarmya’, i.e., achievement of the state of remaining established in one’s own real nature as the actionless Self-which is different from the success arising from Karma (-yoga), and is of the form of being established in the state of immediate Liberation. Accordingly has it been said, ‘…having given up all actions mentally,…without doing or causing (others) to do anything at all’ (5.13). The stages through which one who has attained success-which has the aforesaid characteristics and which arises from the performance of one’s own duties mentioned earlier as worship of God-, and in whom has arisen discriminative knowledge, achieves perfection-in the form of exclusive adherence to Knowledge of the Self and consisting in the state of one free from duties-have to be stated. With this is view the Lord says:

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

18.41-60 Brahmana – etc. upto avasopitat. Surely the intrinsic nature of the Brahmanas etc., does not voilate what has been difined (above) by way of classifying their duties. Therefore, as far as you are concerned, you have the intrinsic quality of the Ksatriya (warrior), and your nature i.e., intrinsic quality, does, without fail, assume the part of the inciter of yourself, even though you don’t like it. For, a person who acts simply being incited by that (natural condition), there is the strong bondage of the merit or demerit. Therefore, perform actions following the means of correct knowledge, taught by Me. In that case, the bondage would disappear. The intention of the principal sentence (statement of the entire passage under study) is to help to get this idea. The meaning of the subordinate sentences (statements) is evident. Briefly (verse 50) : in short. Knowledge : i.e. the one which has been explained earlier. Nistha conveys, avoiding verbal jugglary, the meaning ‘what has been determined’. He who is endowed with intellect totally pure etc. : All this has been almost explained already. Hence, no more trouble is taken [to comment upon it].

Sanskrit Shloka Without Transliteration Marks:

asakta-buddhih sarvatra
jitatma vigata-sprhah
naiskarmya-siddhim paramam
sannyasenadhigacchati

Sanskrit to English Word for Word Meanings:

asakta-buddhiḥ — having unattached intelligence; sarvatra — everywhere; jita-ātmā — having control of the mind; vigata-spṛhaḥ — without material desires; naiṣkarmya-siddhim — the perfection of nonreaction; paramām — supreme; sannyāsena — by the renounced order of life; adhigacchati — one attains.