An even mind toward all three pairs, and the battle incurs no sin.

Advaita Vedānta

These commentators read the call to battle as strictly incidental (prasangika) to the chapter's real subject, which is the supreme vision of the self. The worldly, common-sense reasoning of the preceding verses was offered only to lift Arjuna out of his grief, not as the main teaching. On this reading the verse is a hinge: it sums up the knowledge already given and prepares the scripture to divide cleanly into its two disciplines, the path of knowledge for the Samkhyas and the path of action for the yogins. They press this point hard against an objection some raise here, that since the duty of battle is taught inside a section on realizing ultimate reality, scripture must intend a fusion of knowledge and works. They deny it: the warrior's duty has entered only by the way, and no combination of knowledge and action is established through that pretext.

Śaṅkarācārya · Śrī Ānandagiri

Viśiṣṭādvaita

Here the verse is read as instruction specifically for the mumukshu, the seeker of liberation, and its equanimity is grounded in the knowledge already taught: that the self is eternal, distinct from the body, and untouched by every nature of the body. Because the self is known to be other than the body, the pleasure, pain, gain, loss, victory and defeat that come in war, through the unavoidable falling of weapons, cannot truly reach it, so the understanding can stay unchanged. Most strikingly, these commentators take the 'sin' Krishna promises to avert not as the specific guilt of killing teachers but as the whole painful round of transmigration (samsara); 'you will not incur sin' means you will be freed from the bondage of rebirth. One source argues this carefully: the word cannot mean the suspected guru-slaying guilt (the war's lawful character already removes that), nor past sin, nor future sin, nor mere residue, so it must mean the samsara-prompting karma and the rebirth it implies.

Rāmānujācārya · Vedānta Deśika

Bhakti

These commentators, like the liberation-centered reading, hold that for one who fights 'in the way of one seeking liberation' the sin of destroying teachers and brahmins simply does not arise, and that the seeker of knowledge wipes away even ancient, endless sin. They seal the point with the Gita's own later image, 'he is not stained by sin, as a lotus leaf is not stained by water' (5.10): the equanimous, discerning fighter sheds sin as the leaf sheds water. One of them also meets a fresh objection, that without longing for fruit no one would take up the hard labor of war or charity. His answer keeps a place for longing while purifying its object: it is longing for the endless bliss of the Self that now drives the act, just as longing for a kingdom drives a man to leap from a cliff. So motive is not killed but redirected to the highest goal.

Śrīla Baladeva · Śrīla Viśvanātha

Śuddhādvaita

This commentator frames the verse as the reassurance of a soul anxious that it may already have incurred sin from the prospects weighed earlier ('what is to become of me?'). The remedy is the same even-mindedness toward the body's pleasure and pain, the kingdom's gain and loss, victory and defeat, freed from elation and dejection. What is distinctive is the ground he gives for engaging: one fights 'with regard to My command,' that is, in obedience to Krishna's own word. The act is anchored not chiefly in detached duty but in surrender to the Lord's directive.

Śrī Puruṣottama

Advaita Vedānta

While sharing the common reading, this commentator adds a precise point about how scriptural authority works. Arjuna's worry rests on the general rule 'one shall not harm any creature,' which seems to forbid the war. The answer is that the specific injunction to fight, as a directive aimed at the kshatriya's particular duty, overrides the general prohibition. The special command takes precedence over the general one. With this added to the equal vision that keeps sin from attaching, he concludes that 'the gain is on every side.'

Dhanapati Sūri

Modern

This commentator reads the verse against the backdrop of two whole ways of living in the world: the Samkhya path of renunciation and the Yoga path of action. The point of the verse, he argues, is that Samkhya by itself cannot answer Arjuna's situation. Krishna has shown that pleasure and pain must be borne with an equable mind and that war, fought with such a mind, brings no sin to a kshatriya. But Samkhya holds that everyone's highest duty is to renounce worldly life altogether, so it cannot explain why Arjuna should not renounce on the spot, nor why he should follow the rules of his own caste; on Samkhya's terms his original objection would stand unanswered. The verse therefore marks the turn from the path of knowledge to the path of action, where the answer actually lies.

Lokmanya Tilak

Modern

This commentator stresses that the cause of sin is desire (kamana), not war: cast off desire and stand up to fight. He reads 'papa' here as standing for both sin and merit, papa and punya alike, since both bind, one leading to hell and one to heaven, and both keeping a person turning through birth and death. So established in evenness and doing the duty of war, Arjuna will be bound by neither demerit nor merit. He also widens the teaching past Arjuna's case: performing one's duty-work is necessary for both the desire-driven and the desireless person, and one's turning toward or away from any action should follow scripture, not greed for pleasure or fear of pain. He further sets these verses (31 to 38) in a deliberate pattern, injunction then prohibition then injunction again, and shows the verse answering, point by point, the very arguments Arjuna had made in chapter one.

Swami Ramsukhdas