The sage is awake in the world's night; the world's day is night to him.

Advaita Vedānta

These commentators read the verse as teaching that, once knowledge of the Self has dawned, the knower is qualified for the renunciation of all action and not for engagement in it. The reasoning runs through the night-metaphor. The whole machinery of action (the division of doer, deed, and fruit) belongs to the state of not-knowing, which is like night; with the rising of the sun of knowledge that night is destroyed, and with it the basis for any injunction to act. Before knowledge, a person engages in action because he takes the scripture's command 'this is to be done by me' as valid and binding; the one who has seen that all this realm of distinction is mere not-knowing, like night, no longer takes it that way, so for him the only authority is renunciation of all action and steadfastness in knowledge alone. One source raises the objection that no one acts, or even arrives at knowledge, without some prompting valid means of knowledge, so even the knower would still need a command. The answer given is that knowledge of the Self has the Self for its object, and the Self is not something to be brought about by any command; all the means of knowledge come to rest in the Self once it is reached, just as the means of knowledge of a dream are set aside on waking. So no command applies to the knower at all. One source within this group adds, from a Yoga perspective, that a residue of past-action momentum (prarabdha) keeps the liberated yogi in a body until death, so that the world still presses on him faintly in the post-meditative state like a distressing dark night, and that such yogis are very tender, recoiling from outer dealings as one recoils from moving in dense darkness.

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

Dvaita

These commentators identify the 'night' of the first line as the very own-form of the supreme Lord. The sage is awake there in that he sees the supreme Self rightly, by direct vision. They explicitly resist reading the verse as a teaching about renouncing all action: one source records and rejects the claim 'this verse is for propounding the abandoning of all action by the knower,' on the grounds that the words simply do not say it and that it would contradict other evidence. On their reading the verse gathers up the marks of the man of steady wisdom given in the preceding verses into a single point. They also take 'muni' to mean one joined with reflection (manana), and from this draw a further conclusion: since the verse calls the knower a 'sage' without restricting him to the renouncer's order of life, it is wrong to say that this knowledge belongs only to one who has formally renounced. Sages who were householders, they note, reached knowledge through hearing and reflection. They explain that the sage's moving about and other activity, even though he 'for the most part knows nothing' of the world of objects, is like the movement of a man intoxicated, citing the Bhagavata, and that reflection is named here as the means by which the seeing was reached rather than as something going on at the same time as the seeing.

Madhvācārya · Śrī Jayatīrtha

Śuddhādvaita

This commentator reads 'nisha' through its sense of happiness rather than only as hiddenness, glossing the word as 'that in which there is much happiness.' On this reading the worldly 'night' is the state in which all beings sleep immersed in the pleasures of objects and so attain their kind of happiness; in that night the self-restrained one keeps watch and does not take that happiness for himself. The other 'night,' the one in which beings stay awake but find no happiness, is for the sage of restrained reflection his own attainment of happiness, namely the contemplation of the bliss of Bhagavan. The qualifier 'muni' is used, this source explains, precisely because that bliss is beyond speech.

Śrī Puruṣottama

Bhakti

These commentators frame the verse as showing that for the one of steady wisdom the restraint of all the senses is self-accomplished, answering the doubt that such a person seems impossible to find. They distinguish two kinds of understanding or awareness: one turned toward the Self and one turned toward objects. The Self-turned awareness is 'night' to all beings because, like night to a sleeper, it leaves the higher thing unknown to them; in it the self-controlled one is awake and directly experiences the bliss grounded in the Self. The object-turned awareness, in which beings are awake and directly experience object-bound pleasure, grief, and delusion, is 'night' to the sage; he experiences nothing grounded in it. Two of these sources stress positively that the sage is not merely blank toward the world but looks on the objects that bring others joy and pain with indifference, taking up even the things meant for his enjoyment fittingly and without taint; one illustrates this with the figure of one whose steady attention to a pot balanced on the head holds even while a dancing-girl performs, so that the gaze fixed on the Self does not grasp the relish of anything else.

Śrīdhara Svāmī · Śrīla Viśvanātha · Śrīla Baladeva · Sant Jñāneśvar

Modern

These commentators keep the plain inversion of values and apply it to ordinary life, without the Advaita renunciation-of-all-action argument. One states it simply: what is real for the worldly-minded is illusion for the sage and the reverse, the sage living in the Self as his day and unconscious of worldly phenomena as his night. Another frames it as two divergent paths, the ascetic dead to the world and alive to God, the sensual man alive to the world and dead to the spirit. One reads the metaphor specifically in terms of action and desire: ignorance is darkness and knowledge is light, so desire-prompted action, which ordinary people are steeped in and treat as light, the knower treats as contemptible darkness, while the desireless action the knower likes is disliked by others. The fullest of these develops the contrast at length: he likens people absorbed only in eating, earning, and gathering to animals and birds, noting that men have been given the power of discrimination (viveka) by which they could attain the supreme but largely misuse it to accumulate things they do not even need; he describes how such people stay intensely vigilant over money and land and honor, counting every coin and inch, and how all of this, in the eyes of the reflective self-controlled knower of both the world and the supreme, is like night, mere darkness. This commentator adds two homely images of his own: grown people quarreling over perishable objects are like children quarreling over pebbles and bits of colored glass, glad to get them and grieved to lose them, when one who sees their worthlessness asks what is really gained or lost and how long any of it will even stay; and just as a flaw in the eye makes a film seem to float in the clear sky while the mind stays firmly convinced no such film is really there, so even while the world appears through the senses, the knower's settled conviction abides that in truth there is no world, only an appearance.

Swami Sivananda · Mahatma Gandhi · Lokmanya Tilak · Swami Ramsukhdas