śrī-bhagavān uvāca
kāma ea krodha ea
mahāśano mahā-pāpmā
viddhy enam iha vairiam

Translation of Bhagavad Gita 3.37

The Supreme Personality of Godhead said: It is lust only, Arjuna, which is born of contact with the material mode of passion and later transformed into wrath, and which is the all-devouring sinful enemy of this world.

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

When a living entity comes in contact with the material creation, his eternal love for Krishna is transformed into lust, in association with the mode of passion. Or, in other words, the sense of love of God becomes transformed into lust, as milk in contact with sour tamarind is transformed into yogurt. Then again, when lust is unsatisfied, it turns into wrath; wrath is transformed into illusion, and illusion continues the material existence. Therefore, lust is the greatest enemy of the living entity, and it is lust only which induces the pure living entity to remain entangled in the material world. Wrath is the manifestation of the mode of ignorance; these modes exhibit themselves as wrath and other corollaries. If, therefore, the mode of passion, instead of being degraded into the mode of ignorance, is elevated to the mode of goodness by the prescribed method of living and acting, then one can be saved from the degradation of wrath by spiritual attachment.

The Supreme Personality of Godhead expanded Himself into many for His ever-increasing spiritual bliss, and the living entities are parts and parcels of this spiritual bliss. They also have partial independence, but by misuse of their independence, when the service attitude is transformed into the propensity for sense enjoyment, they come under the sway of lust. This material creation is created by the Lord to give facility to the conditioned souls to fulfill these lustful propensities, and when completely baffled by prolonged lustful activities, the living entities begin to inquire about their real position.

This inquiry is the beginning of the Vedanta-sutras, wherein it is said, athato brahma jijnasa: one should inquire into the Supreme. And the Supreme is defined in Srimad-Bhagavatam as janmady asya yato ’nvayad itaratas ca, or, “The origin of everything is the Supreme Brahman.” Therefore the origin of lust is also in the Supreme. If, therefore, lust is transformed into love for the Supreme, or transformed into Krishna consciousness—or, in other words, desiring everything for Krishna—then both lust and wrath can be spiritualized. Hanuman, the great servitor of Lord Rama, exhibited his wrath by burning the golden city of Ravana, but by doing so he became the greatest devotee of the Lord. Here also, in Bhagavad-gita, the Lord induces Arjuna to engage his wrath upon his enemies for the satisfaction of the Lord. Therefore, lust and wrath, when they are employed in Krishna consciousness, become our friends instead of our enemies.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

Lust, composed of the desire of the sense objects, impels a man to sin. A man, being urged by lust, engages in sin. This lust, appearing in a different form, becomes visible as anger. This means that lust, being obstructed by someone, transforms into anger. Lust arises from the mode of passion, and from lust in mode of passion arises anger in the mode of ignorance.

“But after the fulfillment of desire, the desire should be finished.”

“No, this lust is a great devourer. It is impossible to satisfy the expectations of desire.”

As the smrti says,

yat prthivyam vrihi-yavarm hiranyam pasavah striyah
nalam ekasya tat sarvam iti matva samam vrajet

Understanding that all that is available on earth in the form of food, gold, animals and women is not enough for one person, one should go about with peaceful mind. Mahabharata, Anusasana Parva, Ch.13

“If it is not possible to make an alliance with lust by giving (dana), then is it possible to bring under control by sama and bheda?”

“No, lust is a very great demon (maha papma).”

Commentary by Sri Ramanuja of Sri Sampradaya:

3.37 The Lord said — The highly ravenous desire is born of the Guna Rajas originating from old subtle impressions. It has for its objects sound and other sense contacts. It is a foe to him who is practising Jnana Yoga, as he is joined with Prakrti constituted of the Gunas which rise and subside periodically. It attracts him towards the objects of the senses. It is this desire alone which, when hampered, develops into anger towards those persons who are the cause of such hindrance. It is a powerful cause of sin. It incites the aspirant to do harm to others. Know this, which is born of the Guna called Rajas, as the natural enemy of Jnana Yogins.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

The answer to Arjuna’s previous question is now being answered by Lord Krishna. The main cause for such flagrant behaviour is kama or lust. Also krodha or anger is spoken about but it is actually instigated by lust as well. This is because when kama is unable to satisfy its desires then immediately it takes the form of krodha. This kama is born from rajas guna or the mode of passion. This indicates that when there is an increase of sattva guna or the mode of goodness then kama will be decreased proportionately. It should be clearly understood that kama and krodha are formidable enemies on the path of moksa or liberation from the cycle of birth and death. Both kama and krodha must be terminated by the method Lord Krishna prescribes in the next verses; for it is definitely not appropriate to try to appease either of them as it is useless to try to pacify kama because it has an insatiable appetite and is never satisfied and it is also useless to appease krodha because it is has a terribly temperament and is unpredictably sinful.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

The influence which is the most powerful and destructive on human beings is kama or lust followed by krodha or anger which arises from frustrated desires. Those who hypothesise contrarily are not cognisant of the subtle difference involved in the mixture of the two. Therefore it can be understood that without desire there is no opportunity for anger to manifest and indeed it does not. Since there are many causes of anger it is called mahashanah or great devourer. Since anger becomes the cause of committing abominable actions it is called mahapaapma or great sinner and because it is counter productive to all human goals of righteousness it is called mahavairi or great adversary.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

Lord Krishna is explicitly confirming that the root cause and great impeller of sins is kama or lust known to forcefully compel one’s senses to race impetuously towards objects of the senses. But kama’s subordinate krodha or anger is also the cause of many evils like violence. When lust is impeded and desires are frustrated it is anger that replaces lust in another form. Hence krodha is also a form of kama and both arise out of rajas guna or the mode of passion. This suggests that by increasing sattva guna or the mode of goodnes the effects of rajas guna can be decreased and subsequently the power of desires is less. Because controlling desires one controls lust and controlling lust one controls anger. There is no other way. Thus one should not miss that they are inteconnected and try to control each seperately. But kama is extremely difficult to control once it has been activated because it is insatiable and it does not become tranquil after even enjoying wealth, pleasure of the flesh, kingdoms and even the whole world; to the contrary its desires increases exactly as a fire increases when oil is poured on it, it rages out of control and so it is an extremely evil propensity and when impeded it explodes into anger destroying all in its path like a horrific forest fire.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

3.37 Esah, this; kamah, desire, is the enemy of the whole world, because of which the creatures incur all evil. This desire when obstructed in any way turns into anger. Therefore, krodhah, anger, is also identical with this (desire). It is rajoguna-samudbhavah, born of the quality of rajas; or, it is the origin of the quality of rajas. For, when desire comes into being, it instigates a person by arousing rajas. People who are engaged in service etc., which are effects of rajas, and who are stricken with sorrow are heard to lament, ‘I have been led to act by desire indeed!’ It is mahaasanah, a great devourer, whose food is enormous. And hence, indeed, it is maha-papma, a great sinner. For a being commits sin when goaded by desire. Therefore, viddhi, know; enam, this desire; to be vairinam, the enemy; iha, here in this world. With the help of examples the Lord explains how it is an enemy:

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

3.37 Kama esah etc. A total absence of difference among these two (desire and wrath) is indicated by the word esah ‘this’ twice uttered. These desire and wrath are ever interrelated and remain in an inseparable mutual co-existence. Hence [the Lord] well describes them only as identical. This is a swallower i.e., a devouer of the morsel of festival i.e., the happiness. The wrath alone is a bestower of sins as it is the cause of great sins. This is man of intelligence should view to be an enemy.

Sanskrit Shloka Without Transliteration Marks:

sri-bhagavan uvaca
kama esa krodha esa
mahasano maha-papma
viddhy enam iha vairinam

Sanskrit to English Word for Word Meanings:

śri-bhagavān uvāca — the Personality of Godhead said; kāmaḥ — lust; eṣaḥ — this; krodhaḥ — wrath; eṣaḥ — this; rajaḥ-guṇa — the mode of passion; samudbhavaḥ — born of; mahā-aśanaḥ — all-devouring; mahā-pāpmā — greatly sinful; viddhi — know; enam — this; iha — in the material world; vairiṇam — greatest enemy.