niyatasya tu sannyāsaḥ
karmaṇo nopapadyate
mohāt tasya parityāgas
tāmasaḥ parikīrtitaḥ

Translation of Bhagavad Gita 18.72

Prescribed duties should never be renounced. If one gives up his prescribed duties because of illusion, such renunciation is said to be in the mode of ignorance.

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

Work for material satisfaction must be given up, but activities which promote one to spiritual activity, like cooking for the Supreme Lord and offering the food to the Lord and then accepting the food, are recommended. It is said that a person in the renounced order of life should not cook for himself. Cooking for oneself is prohibited, but cooking for the Supreme Lord is not prohibited. Similarly, a sannyasi may perform a marriage ceremony to help his disciple in the advancement of Krishna consciousness. If one renounces such activities, it is to be understood that he is acting in the mode of darkness.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

Starting the description of the three types of tyaga, the Lord here describes the tamasic tyaga. Giving up daily activities (niyatasya karmanah) is not recommended. To reject the nitya karmas out of ignorance of the meaning of scriptures (mohat) is called tamasic tyaga. The sannyasi can reject kamya karmas since they are not obligatory, but nitya karmas are not to be rejected. That is the suggestion of the word tu. The result of such tamasic tyaga is ignorance, instead of attainment of knowledge, which was the very goal in rejecting the nitya karma.

Commentary by Sri Ramanuja of Sri Sampradaya:

18.7 Obligatory acts consist of daily, and occasional ceremonies like the five great sacrifices; their abandonment is not proper, for without actions even the sustenance of the body would be impossible, as already stated: ‘From no-work, not even the body can be sustained’ (3.8). The sustenance of the body by eating the sacrificial remnants produces perfect knowledge. Otherwise, as declared in the statement, ‘But the sinful ones eat sin’ (3.13). The satisfaction that comes by eating food which is not the remnant of sacrifice and which is therefore of the form of sin, is productive of erroneous knowledge in the mind. For, as declared in the Sruti, ‘The mind consists of food’ (Cha. U., 6.5.4), the mind is sustained by food. Also, there is the Sruti text, ‘When the food is pure, the mind becomes pure; when the mind is pure, remembrance becomes firmly fixed; and when remembrance is acquired, there is release from all knots of the heart’ (Ibid., 7.26.2). It is therefore proved by the Sruti that knowledge of the form of direct perception of Brahman, is dependent on the purity of food. Hence the great sacrifices and such other obligatory and occasional rites are worthy of adoption till one’s death, as they help in the knowledge of the Brahman. The renunciation of these is therefore not proper. Thus, the relinquishment of these acts which produce knowledge through the delusion that they bind the self, is rooted in Tamas. Tamasika renunciation has its roots in Tamas. Since such renunciation has its roots in ignorance which is the effect of Tamas, such renunciation is said to have its roots in Tamas. For Tamas is the root of ignorance as has been stated: ‘From Tamas arise negligence and delusion, and also, ignorance’ (14.17). Ignorance is erroneous knowledge which is antagonistic to right knowledge. So, it will be taught, ‘That reason which, enveloped in Tamas, regards wrong as right, and which reverses every value, O Arjuna, is Tamasika’ (18.32). It is for this reason that the renunciation of obligatory and occasional actions are said to have their roots in erroneous knowledge.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

The three kinds of renunciation introduced previously are being explained by Lord Krishna in this verse and the next two. Renunciation of actions prompted by desire is proper since such actions assure bondage in samsara the perpetual cycle of birth and death. But giving up prescribed Vedic activities and obligatory duties is not proper since those activities lead to moksa or liberation from material existence by purifying the mind. Therefore abstaining from these sanctifying Vedic activities arises from illusion and the conception to oppose what is prescribed in the Vedic scriptures is delusion. This delusion is understood to be clearly situated in tama guna the mode of ignorance.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Lord Krishna reiterates that abandoning desire for the rewards of actions is what is to be relinquished and the true expression of renunciation. Merely giving up the actions is an erroneous display of foolishness with no benefit. The Padma Purana states: Those who give up the performance of prescribed Vedic activities, receiving no benefits will undoubtedly be forced to enter the dark and hellish nether worlds.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

The Supreme Lord Krishna delineates the three types of renunciation associated with prescribed Vedic activities. Prohibited actions and acts of adharma or unrighteousness as well as any activity motivated by a desire other then the satisfaction of the Supreme Lord are undoubtedly to be abandoned. But renunciation of prescribed Vedic activities results in evil and inauspiciousness acts that propel one to hellish destinations. An example is not following ekadasi or fasting from all grains on the 11th day of the waxing and waning new moon and full moon. If one renounces this injunction one will certainly have to suffer in a hellish condition of life. So to disregard and ignore prescribed Vedic activities is not appropriate or advisable because these activities help to purify the mind. To relinquish what is benefical due to indifference, indiscretion or indiscrimination has been declared as situated in tama guna or mode of ignorance because such renunciation reveals the presence of inertia and nescience.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

18.7 Therefore, sannyasah, the abandoning; niyatasya tu karmanah, of the daily obligatory acts, by the seeker of Liberation who is as yet unenlightened and is fit for rites and duites; na apapadyate, is not justifiable, because what is desired is the purification of unenlightened persons. Parityagah, giving up; tasya, of that, of the daily obligatory duty; mohat, through delusion, through ignorance; parikirtitah, is declared; to be tamasah, based on tamas. Niyata is that duty which must be performed. That an act is niyata (obligatory) and it is relinquished is contradictory. Therefore the giving up of that through delusion is declared to be based on tamas, for delusion is tamas. Besides,

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

18.4-11 Niscayam etc. upto abhidhiyate. The conclusion here is this : Due to the manifoldness of the nature of the Strands, that have been defined earlier, the act of relinquishment itself is performed with a certain mental disposition which is a modification of the Sattva, the Rajas and the Tamas (the Strands). Because it reflects (is contaminated by) the nature of the person having the same (the said mental dispositon), what is called the real (unalloyed) relinquishment is the performance of the actions by the knowers of the Supreme Brahman by giving up desire to achieve fruits and by avoiding the craving and hatred on account of their equanimity to [the pairs of opposites like] success and failure etc. That is why [the Bhagavat] says : ‘By the act of relinquishment born of the Rajas or of the Tamas (Strands), no connection with the fruit [of relinquishment] is attained’. However, for an act of relinquishing, born of the Sattva (Strand), there is the fruit in the form of honouring the purport of the scriptures. The application of the term ‘relinquishment’ stands to reason, in fact, only in the case of a sage who has relinquished his holding on the multitude of the Strands.

Sanskrit Shloka Without Transliteration Marks:

niyatasya tu sannyasah
karmano nopapadyate
mohat tasya parityagas
tamasah parikirtitah

Sanskrit to English Word for Word Meanings:

niyatasya — prescribed; tu — but; sannyāsaḥ — renunciation; karmaṇaḥ — of activities; na — never; upapadyate — is deserved; mohāt — by illusion; tasya — of them; parityāgaḥ — renunciation; tāmasaḥ — in the mode of ignorance; parikīrtitaḥ — is declared.