Death is certain for the born, birth for the dead; grief over the unavoidable is misplaced.

Viśiṣṭādvaita

These commentators take the harder half of the verse, that the dead are certainly born again, and ground it in a careful theory of substance: only what already exists can originate, never what is wholly non-existent. On this view, origination and destruction are not the appearing and vanishing of separate things but only successive STATES of one persisting substance. The standing example is clay, which passes through lump, pot, potsherd, and powder. A substance reaching a later state IS the destruction of the earlier state and, in the very same act, the origination of the later one. So when a thing 'dies' it has only passed into a contrary state of the same underlying substance, and its rebirth is just that one substance arriving in a further state. Read this way the rebirth of the destroyed is no paradox at all, and since such succession of states cannot be averted for anything that changes, grief over it is uncalled for. One source develops this at length against the rival view that the effect does not pre-exist, arguing that no extra whole-substance beyond the arranged parts is ever actually perceived, and that treating destruction as a mere later state, rather than as a separate negative thing, accounts for all our ordinary talk of a thing being and not being.

Rāmānujācārya · Vedānta Deśika

Advaita Vedānta

This commentator reads Arjuna's fear as twofold and answers both halves with the single phrase 'in an unavoidable matter.' There is the visible, this-worldly sorrow of the kinsmen dying, which is met by pointing out that they perish of themselves through the exhaustion of their karma and Arjuna cannot prevent it. And there is the unseen sorrow of incurring sin by fighting, which is met by holding that war is a duty enjoined upon a kshatriya, fixed like the daily Agnihotra fire-offering; arising from a root meaning 'to clash,' lawful battle, like the prescribed violence of certain Vedic sacrifices, produces no demerit, with the tradition cited that there is no fault in killing in battle except against the unarmed or unhorsed. Hence even fear of unseen harm gives no ground for grief, since omitting an enjoined war would itself bring sin.

Madhusūdana Sarasvatī

Advaita Vedānta

This commentator deliberately sets aside the attempt to load the verse with 'unseen suffering' as a further cause of Arjuna's fear, judging it forced and not warranted by the words. He likewise rejects reading the verse as still confined to the doctrine of the Self's eternity; rather the Lord adopts each position in turn to teach by an argument from the stronger case. The verse's whole point, he insists, is simply that the cycle of birth and death is unavoidable, so grief over it makes no sense, and this holds on every theory of the Self alike, whether one takes it as all-pervading, as momentary, or as a thing now absent and now present. He recalls the sage Vasishtha's counsel to Rama: if you existed before, exist now, and will exist hereafter, why grieve for kinsmen who likewise span past, present, and future, the Self being changeless throughout.

Dhanapati Sūri

Śuddhādvaita

This commentator turns the unavoidability into the work of God as the one who arranges all things. For whoever has taken birth, death has already been appointed by the divine Arranger; so the death of these men, which Arjuna imagines himself to be causing, will come about exactly as it has already been arranged. The matter is not merely unavoidable but utterly fated by the Lord, and the pointed question is: who else can undo what God has done? On this reading Arjuna is plainly not the agent of these deaths, and grief, which assumes he is, falls away.

Śrī Puruṣottama

Bhakti

This commentator first frames the verse on the view of 'the logicians,' for whom the Self is eternal and distinct from the body: joining a fresh body and senses is birth, parting from the old ones is death. Crucially, since birth and death are caused by merit and demerit, they must belong primarily to the eternal Self as their substrate and only secondarily to the perishable body; for if the impermanent body were their true substrate, then action done would fail to bear its fruit and fruit would accrue for action not done, which cannot be. So even taking the Self as the real bearer of these events, the eternal Self too is 'certain' to undergo the death fixed by exhausted karma and the birth fixed by fresh karma, and a learned man ought not to grieve. He adds the practical edge that withdrawing from battle saves no one, since these men die when their karma is spent, while Arjuna would only incur the fault of deserting his own duty.

Śrīla Baladeva

Kashmir Shaivism

This commentator runs the verse through a series of opposed doctrines to show that none leaves room for grief. If you hold the body to be constantly born, its stream is never broken, so there is no loss to mourn; if by the doctrine of momentariness you hold it constantly destroyed, then mourning a single passing makes no sense either. The same applies to the self: whether you think it constantly born or constantly dying through its joining and parting with one body after another, grieving is in every way improper for those who proceed by the means of knowledge. The verse thus disarms grief on every metaphysical option at once.

Ācārya Abhinavagupta

Modern

This commentator stresses that this argument is not the Gita's own teaching but a reply to the merely assumed proposition raised earlier by the word 'or.' The Gita's actual doctrine, he reminds us, is that the Self is existent, unborn, immutable, and beyond quality. Here, by contrast, the Lord argues on the basis of the Samkhya system that there should be no lamentation over the body precisely because the body is non-permanent. The whole aim of the stanza is only to show that on either supposition, the Self taken as permanent or as impermanent, lamentation has no place.

Lokmanya Tilak