Advaita Vedānta

For these commentators the inward turn is the recognition of the one non-dual Self, and brahma-nirvana is the dissolving of imagined duality. The happiness, play, and light are not three new acquisitions but the Self's own nature, uncovered when the veil of ignorance lifts. The freed person is 'ever Brahman itself,' so attainment means the ending of a false cognition, not the gaining of an unattained object: in absorption the world of sound and form does not appear, and even when it appears afterward it is known as false, so no real pleasure is taken in it. One source frames the outer world across waking, dream, and sleep as fashioned upon the Self, unreal and painful, no playground at all, with brahma-nirvana like re-finding an ornament one had forgotten one was wearing; the same source cites the Kashakritsna view that the supreme Self abides as the individual self, so the apparent jiva-Brahman relation is consistent with their identity.

Śaṅkarācārya · Śrī Ānandagiri · Madhusūdana Sarasvatī · Śrī Nīlakaṇṭha · Dhanapati Sūri

Viśiṣṭādvaita

Here the 'within' is the experience of the self (atman) as one's single happiness, with the self itself, by its own qualities, being the increaser of that happiness. Brahma-nirvana is read positively as 'the happiness of the experience of the self,' the resolved state where the disturbances of the outer have lapsed. One source is explicit that 'nirvana' must not be heard in the extinction-language of an alien (Buddhist) school: it is rest in Brahman, and the verse simply gives more body to the earlier line 'one finds the happiness that is in the self.' What was renounced, the enjoyable nature-stuff and the instruments of enjoyment, is now reimagined as resting in the self so that one may relish the self alone.

Rāmānujācārya · Vedānta Deśika

Bhedabheda

This commentator reads the three 'withins' plainly: happiness, play, and light all rest in the inner Self, and the inner light is contrasted with the outer lights of wind, sun, and the like. He glosses the attainment as 'the supreme yoga,' that which is joined to Brahman, the supreme Self, reached by one who has become Brahman. He then adds a further scriptural line about seers whose impurities are exhausted and doubts cut away, who delight in the welfare of all beings, attaining the peace of Brahman, bridging into the next verse.

Śrī Bhāskara

Dvaita

For these commentators the inward light is specifically the self-luminous Lord, the supreme Vishnu, abiding and shining within the heart; the 'light' belongs primarily to Him because He alone shines without depending on another. Inner happiness is the joy that rises from seeing the supreme Self, and from the ceasing of desire. They are careful that 'become Brahman' (brahma-bhuta) be analyzed as 'become situated in Brahman,' not 'become Brahman itself,' since identity would conflict with the means of valid knowledge; and 'he attains' is to be read as 'he knows.' One source cites the Naradiya that arama is the happiness from seeing, touching, and conversing, and that the inward light is the great Vishnu's self-luminous abiding within. They also note that the word 'alone' (eva) excludes nothing real about the outer, since even when the outer is seen it accomplishes nothing and causes no distraction.

Madhvācārya · Śrī Jayatīrtha

Śuddhādvaita

For the Pushti-marg the inward happiness is the very mark by which the Gita's brahma-nirvana is to be recognized, and it is read through devotion to Krishna. One source describes the freed yogin as a living jivanmukta for whom the outer world keeps its colors and motions yet has ceased to bind, a mere theatre of the Lord's lila; brahma-nirvana is not an outer disappearance but the soul's coming to rest in Purushottama from whom it never was truly apart. The other source goes further: the inner happiness, delight, and light are the rasa of conjunction with Krishna, held even through seeming separation, so that brahma-nirvana is not extinction into a featureless absolute but the soul, become bhava-bodied, dissolving into the Lord's own play. The saint's interior is not a vacancy but a hidden Vrindavan lit by the unbroken presence of the Lord-of-rasa.

Vallabhācārya · Śrī Puruṣottama

Kashmir Shaivism

This commentator gives the verse a terse, striking turn: the happiness, delight, and light are within, depending on nothing outer, while in worldly dealing the freed person appears 'as if dull' or insentient. He cites the saying that one whose mind is beyond disputation should move about as if without sense, marking the gap between the inward fullness and the outwardly unremarkable behavior.

Ācārya Abhinavagupta

Bhakti

These commentators stress that the three inwardnesses are inward from the very start, not first sought outside and then withdrawn: the joy is not gathered back in, the play is not collected back in, the seeing is not turned back in; each was always an inward thing, and only one for whom all three are inward is fit to be called the candidate for brahma-nirvana. One source reads brahma-nirvana as laya, dissolution into Brahman, and says the verse is not a blanket discouragement of outer enjoyments but a description of the temperament whose center has already moved inward, so release is a homecoming. The other, the Marathi Jnaneshwari, breaks into praise of such saints as the very embodiment of joy and the dwelling-place of Self-realization, then has the listeners gently rein in the flowery praise and return to the teaching.

Śrīdhara Svāmī · Sant Jñāneśvar

Modern

These voices read 'within' as 'in the Self' and brahma-nirvana as liberation while living, becoming a jivanmukta. One frames it through karma-yoga: the yogin has become internally happy in his conscience without laying store by outer happiness or unhappiness, has found tranquility within, and so attains release as being merged and unified with Brahman. Another gives a careful phenomenology: outer (bahya) is what is not always available and not available to all; inner (abhyantara) is what is always available and to all. On this footing he distinguishes the three: antah-sukha rests in the supreme Self alone and the self gives itself no sorrow and feels no aversion to itself; antar-arama delights only in the supreme and acts, even while acting, in the supreme alone; antar-jyotih is the knowing of the supreme that illuminates and grounds all sense-knowing and intellect-knowing, and unlike worldly knowing it has neither beginning nor end.

Swami Sivananda · Lokmanya Tilak · Swami Ramsukhdas