yathā prakāśayaty ekaḥ
kṛtsnaḿ lokam imaḿ raviḥ
kṣetraḿ kṣetrī tathā kṛtsnaḿ
Translation of Bhagavad Gita 13.34
O son of Bharata, as the sun alone illuminates all this universe, so does the living entity, one within the body, illuminate the entire body by consciousness.
Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:
There are various theories regarding consciousness. Here in Bhagavad-gita the example of the sun and the sunshine is given. As the sun is situated in one place but is illuminating the whole universe, so a small particle of spirit soul, although situated in the heart of this body, is illuminating the whole body by consciousness. Thus consciousness is the proof of the presence of the soul, as sunshine or light is the proof of the presence of the sun. When the soul is present in the body, there is consciousness all over the body, and as soon as the soul has passed from the body there is no more consciousness. This can be easily understood by any intelligent man. Therefore consciousness is not a product of the combinations of matter. It is the symptom of the living entity. The consciousness of the living entity, although qualitatively one with the supreme consciousness, is not supreme, because the consciousness of one particular body does not share that of another body. But the Supersoul, which is situated in all bodies as the friend of the individual soul, is conscious of all bodies. That is the difference between supreme consciousness and individual consciousness.
Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:
Using an example, the Lord shows how the paramatma, being the source of illumination, is not connected with the qualities of what he illuminates. Just as the sun, the illuminator, is not connected to the qualities of what he illuminates, the paramatma (ksetri) illumines everything and is not affected. The sruti says:
suryo yatha sarva-lokasya caksur
na lipyate caksusair bahya-dosaih
ekas tatha sarva-bhutantaratma
na lipyate soka-duhkhena bahyah
Just as the sun is the eye of all people but is not contaminated by the material faults of the eyes, so the paramatma within all beings is not contaminated by lamentation and suffering of the material world. Katha Upanisad 5.11
Commentary by Sri Ramanuja of Sri Sampradaya:
13.34 As the ‘one sun’ illumines ‘all this world’ by his radiance, so the ‘knower of the body’ illumines the entire Ksetra, i.e., the body, by Its own knowledge, within and without and from head to toe, by conceiving ‘This my body is of this nature.’ This self of the said nature is totally different from the body, because It is the knower of the body. The body is the object of Its knowledge and is therefore different from It, even as the illuminating sun is totally different from the illumined world.
Commentary by Sri Sridhara Swami of Rudra Sampradaya:
By the example of ether in the previous verse the atma or immortal soul was shown to be impervious to situation of the physical body. Now Lord Krishna gives the analogy of the sun illuminating the whole universe as in the same way that paramatma the one Supreme Soul illuminates all individual souls and each individual atma illuminates with consciousness the entire physical body of the jiva or embodied being but is not affected by the properties or activities of the body.
Commentary by Sri Madhvacharya of Brahma Sampradaya:
Sri Madhvacharya did not comment on this sloka.
Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:
It may be even further postulated that paramatma the all pervading Supreme Soul may be existing equally in the atmas or individual immortal souls of all jivas or embodied beings as was previously alluded to regarding the ether. That can be accepted fully as both the atma and paramatma are eternally spiritual; but for the atma to be like ether throughout the physical body denotes its omnipresence and thus it is exposed to the pain and pleasure, joy and despair which the physical body experiences. Also by what criteria is an atma to be measured. Would the atma of a human be too big for an ant and if subsequently an ant would have to take birth as an elephant would its atma be too small? Yet again if it is to be accepted that the atma is sub-atomic in size how will it be possible to experience pleasure and pain as well as complete body luminosity because as the Vedic scriptures confirm it is residing in the etheric heart of all jivas?
To alleviate all these doubts and misconceptions, Lord Krishna the analogy that as a single sun is able to prakasyati or illuminate an entire universe; in the same way from within the etheric heart the atma is able to illuminate the entire physical body by the medium of consciousness. The atma is neither omnipresent nor modifiable in size not because of the questions previously posed but because of the verdict of the Vedic scriptures. The Mundaka Upanisad III.I.IX beginning eso anuratma cetasa veditavyo states: The soul is infinitesimal in size and is realised directly by the mind which has neutralised completely all effects and influences of the five senses which reveals the enlightenment of the soul. In the Svetasvatara Upanisad V.VIII beginning balagrashata bhagasya states: The atma is known to be as subtle as 100th part the size of the tip of a hair that again was divided into a 100th parts which equals 1/10,000 the tip of a hair. The Prashna Upanisad III.VI beginning hrdi hyesha atma states: The atma resides in the heart where there are 101 nadis or nerves and for each nadi there are 100 sub-nadis and each of these sub-nadis has 72,000 subordinate nadis. The Vedanta Sutra II.III.XXIV beginning gunadva lokavat states: The atma although residing in the heart by its quality of consciousness illuminates the physical body as a light illuminates a room. So from all these relevant examples given in the Vedic scriptures all discrepancies are dispelled.
Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:
13.34 Yatha, as; ekam, the one; ravih, sun; prakasayati, illumines; imam, this; krtsnam, whole; lokam, world tatha, similarly;-who?-ksetri, the Knower of the field, i.e. the supreme Self, though one; prakasayati, illumines; krtsnam, the whole; ksetram, field, from the ‘great elements’ to ‘fortitude’ (cf. 5-6). Here the illustration of the sun serves to highlight two aspects of the Self, viz that, like the sun, the Self is one in all the fields, and that It remains unaffected. This verse is meant for summarizing the idea of the whole of this chapter:
Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:
13.31-34 Yada etc. upto na upalipyate. When [a man of Yoga] perceives the mutual difference i.e., separateness of all beings (all mutually different beings) in the very Self on account of Its all pervasive nature and realises the said difference as having sprung up from the Self alone – even then he does not get any stain. For [in that case] he would be the creator (or performer) of all. For, he is none but the Supreme Self; and though residing in the body, he is not stained just as the Eather is [not stained].
Sanskrit Shloka Without Transliteration Marks:
yatha prakasayaty ekah
krtsnam lokam imam ravih
ksetram ksetri tatha krtsnam
Sanskrit to English Word for Word Meanings:
yathā — as; prakāśayati — illuminates; ekaḥ — one; kṛtsnam — the whole; lokam — universe; imam — this; raviḥ — sun; kṣetram — this body; kṣetrī — the soul; tathā — similarly; kṛtsnam — all; prakāśayati — illuminates; bhārata — O son of Bharata.