Lord Krishna said: The imperishable peepul tree, whose leaves are the Vedic hymns, is said to have roots upward and branches downward. Whosoever knows that, understands the import of the Vedas.

Lord Krishna is bringing a significant illustration to depict the mysterious Creation, linking Vedas as the knowledge treasure that explains the process amply. Some trees have amazing longevity, like Banyan and Peepul. But, however long its lifespan is, it is also perishable. That is why it is called “A-śva-ttha”, meaning that which will not be there tomorrow. The Banyan tree in Kolkata Botanical gardens has already lived for over 1200 years. The tree has spread so much all around with numerous secondary roots from the branches that it is hard to find its original trunk. Think of Creation as a time-less tree. The contrast is that it is inverted, with roots above and branches spreading below. We can deal only with its branches and leaves. The cosmic tree will continue to grow, spreading in various directions, as modern science also finds. Universe is expanding, not circumscribed or bounded in any way. Seeing the world-tree, man will have his own curiosity, enquiries, bearing upon the tree as well as his own life and needs, immediate as well as ultimate. It is such yearning that makes life meaningful, comfortable and fulfilling. In answer to this, Krishna brings the immortal Vedas, which have the sole purpose of providing adequate knowledge to live in the world with wisdom, contentment and fulfilment. Vedas are a treasure-house of spiritual and subjective wisdom, different from the secular knowledge academic centres teach. As a tree is known by studying its leaves, the secret of the world as well as the ultimate truth about Creation is known from the Vedas. For this reason, Vedas are considered revelatory. They enlighten the human about himself, the world around, and the interactions between the two. Vedic revelations reach their acme in the Upanishads, the last section of the four Vedas. As long as Vedas and Vedic Upanishads are there to guide us, we have full access to the very source of Creation. Upanishads exhort man to realize this inner source, be enlightened and fulfilled.

Nourished by guṇas, its branches extend downwards and upwards, with their tender sprouts of sensory objects. Its roots also spread below in the human world, giving rise to bondage engendered by activities (prompted by rāga and dveṣa towards their results).

The endless world which is considered an inverted tree without any beginning, Krishna says, is widely spread out above as well as below. The situation above is beyond our reach, But it must be like what we see here; branches of the same tree! Surrounding our earth are countless clusters of celestial bodies, including sun and moon. What about the endless stars at infinite distances? What all are present in these, is beyond our comprehension! Our scope is limited to dealing with the branches extended towards us. Nature’s guṇas – sattva, rajas and tamas – nourish the branches of this eternal tree. Kṛṣṇa also says that humans shape and extend this world-tree by means of their desire-motivated activities, resulting in bondage. In fact, the growth and extension of human race anywhere depend on their own discretion and will. We can increase and decrease our population as we decide. Likewise, it is up to us to migrate to newer areas and settle there. This is meant by “casting secondary roots and branches below”. Who knows whether people will go to the moon also one day and decide to settle there? As long as man craves to enjoy the world which is but a play of guṇas, as long as he is attached to the desire-motivated activities and their fruits, he will not be able to get back to his supreme spiritual identity. He will be lost in the ever-changing leaves and branches of the cosmic tree. So, Kṛṣṇa reveals the way to freedom – how to go beyond the quagmire of this cosmic tree, the endless chain of birth and death.

Neither its form, beginning and end, nor details of its foundation are within our reach. Having felled this firmly rooted Aśvattha tree using the strong, sharp weapon of asaṅga (dis-attachment); Enquire thereupon into that abode, reaching which people do not return again, the means of enquiry being: "I seek that supreme primordial Puruṣa, from whom has emanated this most ancient process of creation."

Krishna makes it very clear that the Universe, the stupendous display, is incomprehensible in every way. Anyone who enquires into it, will find it to be beginning-less. How can one think of understanding and evaluating it then in any manner? To understand anything, we must be able to have access to its origin, birth. If that is not possible, at least we must be able to see it in full, what its measure and magnitude are. Or at least we must be able to know how it ends, if at all. Only when all these are unravelled properly, the understanding of what we want to know will become meaningful. But in the case of the Creation, none of these three – the source, sustenance or dissolution – are visible or accessible at all. Apart from the fact that we are living on earth, which is but one of the myriad planets in space, what do we know about the extent of Creation? At the same time, we are in it; it surrounds us, making it impossible to avoid it the least. What is the way then, to deal with it effectively? It is a legitimate question, for which there must be a definite answer. Let the inverted tree of Creation be there, with its own origin, sustenance and dissolution. We shall deal with those branches which grow around us, to enable our activities and interactions to be facile. The weapon we use to cut and remove the branches growing in our direction is asaṅga, meaning we should have no delusional clinging in our mind to anything. Asaṅga is unlike the knife or sword made of metal. It is an inner weapon, a quality our mind relishes cultivating. As one develops saṅga, so he can also inculcate asaṅga. The former is a result of ignorance, the latter an impact of knowledge, purity, and inner harmony. It will enable the seeker to have spiritual ecstasy of freedom. Holding well on to this asaṅga, says Kṛṣṇa, the seeker must take up the grand spiritual enquiry as to where lies that abode, reaching which none ever returns to this world. And in doing so, he must have a full note of submission and attunement to the Supreme, from where all activities and their outcomes transpire. This attitude is the key for spiritual seekers to lead their pursuit unfailingly and have the desired outcome and fulfilment.

Those, who are free of pride and delusion, have won over the defect of attachment, who are given to constant reflection on the Supreme Reality, and are fully rid of desires; who have overcome the hold of pairs of opposites in the form of sukha and duḥkha, they become free of delusion and reach that supreme imperishable Abode.

Analyzing the nature of the world, Krishna elucidates the means to get freedom from all its binding effects. He says true spiritual pursuit purges the mind of all its dross, like undue self-respect, delusional clinging, etc. It also eliminates the stranglehold of desires from one’s heart. To win over the world is to rise above sukha and duḥkha, the dual outcome the world produces. This makes one enlightened, and enables him to reach the imperishable Abode within.

That is My supreme Abode, which neither sun nor moon nor fire illumines, on reaching which there will be no return or rebirth.

Around us is the sensory world. Our senses reveal the objects in the manner we perceive them. Other objects not perceivable to the senses are known through inferences based on sense perceptions. Sun, moon, fire, etc. shed physical light to reveal world objects to our eyes. But what is that light which reveals the imprints of objects our mind makes within? Besides, there are countless thoughts, emotions, reflections, enquiries, pursuits and findings – all inner. Put together, are they not far greater than the sensory world? Which inner light reveals all these? That is the sovereign spiritual effulgence, which inspires and leads the intelligence, mind and senses for their cognitive and other sensory functions. That is first, all others come next. Krishna says, neither sun nor moon nor stars can penetrate the inner horizon, where reigns the Supreme, inaccessible to everything in the visible world!

An eternal part of Me (the Supreme) becomes the jiva (individual soul, manifesting the power called life) in the world of living beings. By drawing upon the elemental nature it forms the five senses and the mind.While taking up this body and while exiting it, the Lord (Īśvara) brings in and takes away these sensory powers, like wind carrying fragrances from their seats (sources).

First, Krishna pointed out that the supreme Brilliance reigns within the body as the source of all outer brilliancies. Now he explains its function, enabling seekers to grasp it further. The spiritual brilliance called the soul residing in the body is a part of the supreme Reality itself. Called jīva, to begin with, it is the one that draws from Nature all the powers to the senses, which are but parts of the material body. Inner splendour alone instils into the senses the power to cognize. Likewise, the same inner sentience takes away the cognitive powers of the senses while leaving the body (making the body non-functional), just as the wind draws away fragrance from flowers. The soul or jīva in the body alone holds the powers of cognition. See, the cornea from a dead body when grafted to a living body, begins to see. It is true of other organs also, proving that the ultimate cognition of sensory functions depends on the inner spirit. This soul or jīva is really not different from the divine Puruṣa, existing within us as the immortal Soul. But its real unchanging identity remains hidden from us by the variegated changeful appearance projected by Nature. Birth marks the commencement of the sensory functions and death denotes the dysfunction of the same senses. Birth and death are not to the Soul, but only to the body and senses. This is what Kṛṣṇa said in the 2nd chapter also. Death is no extinction but only a transition (2.13).

By presiding over the ear, eye, skin, tongue, nose and also the mind, it (the jīva) enjoys the (multiple qualities of) world objects.

Krishna first explained how the jīva imbibes various properties from Nature’s elements and infuses them into the embodied being. He also explained how the jīva, in the end, takes away these properties, rendering the body non-functional. He now details how inhering in the body, the jīva experiences endless objects and interacts with them, generating knowledge and memory, which distinguish the human from all the rest. It presides over all the sensory perceptions giving rise to sound, touch, taste, colour and smell, through the ear, skin, tongue, eye and nose. It also presides over the inner organ called the mind, thereby experiencing multiple world-objects. But for the Soul, neither embodiment nor the large variety of outer and inner experiences would have been possible. Experiencing is a power of the spiritual presence, the Soul. In fact, the body with all its organs is a medium the Soul has created to undergo experiences.

The deluded do not perceive the Soul in Its leaving the body or residing in it, or even while experiencing sensory objects, being associated with the guṇas. Those with the eye of wisdom, however, perceive It.

Krishna points to three occasions, which equally indicate the presence of the sentient Soul in the body: in the formation of the body in the womb and its birth therefrom; in the continued presence in the body thereafter; in the final transition called death when the soul seemingly exits, making the body lifeless. The soul-presence is like the blazing fire in firewood, the flame in a lamp. Due to sheer delusion, people do not recognise the presence of the Soul in any of the three phases. They believe senses fetch sensations. But the fact is that the inner presence alone animates the senses, taking imprints of objects every time. Until intelligence makes a discreet analysis, this truth will not come to light. But those given to the path of wisdom recognize the difference between the inert body and the sentient presence in it. The others grievously miss it!

Striving seekers perceive the supreme Reality as abiding in their own within. However, those who lack purity as well as discrimination fail to perceive the same, even if they strive hard.

The presence of the Soul in the body is not a matter of doubt. Krishna had explained it right from the 2nd chapter (2.12). The discussion thereafter is based upon this fundamental fact. And staunch seekers do realize the Self in them without any difficulty, as they are able to think about the matter very clearly and wholesomely. Yet many, nay most, fail to realize the Self, as they lack the requisite degree of purity of mind and discrimination of intelligence (viveka). Seeking the Self is not just an intellectual pursuit at all. The impetus is to be provided by the mind and heart. Only when seekers have the required measure of inner purity and austerity, will their wish and resolve grace their effort. As Krishna stated while discussing Sthita-prajñā and Sthita-dhee (Ch 2), the seeker must be free of desire, ego and possessiveness, which are the main hindrances to realize the Self. Purity implies extinction of these three.

Know the brilliance of the sun that illuminates the entire world, the brilliance in the moon and also in the fire, to be from Me (the Supreme).

Krishna removes all shades of doubt about the nature and potential of the Self. The world is what our senses see and show. All its variety is wrought by our five senses. To the objects, eyes bestow brilliance, ears bestow sound, nose smell, tongue taste and skin touch. Objects have no independent status or potential. Their potentials are imparted to them by senses in our body. Wherefrom does the sun have its brilliance? Our eyes alone show the sun as brilliant. That brilliance is from the Self. How does the inner Self bestow external brilliance? Self alone has evolved our body, of which senses are a part. It imbues each sensory organ with its power. Eyes gift colour and brilliance to the objects. Nothing besides the eye can bestow luminosity. Eyes reveal the sun. The inner mind reveals the eyes. The inmost 'I' is what reveals the intelligence, through it the eyes and through the eyes the sun. Thus the one source of all outer and inner brilliances is the Self.

Permeating earth, I (the Supreme) sustain beings with My splendour. Becoming lunar lustre, I nourish all herbs and vegetation with sap.

Krishna first referred to the luminaries like the sun being illumined by the Supreme. Here now he denotes how the same inner splendour enters the entirety of the earth and thereby supports all forms of vegetation. For supporting life on earth, we need sunlight and sunrays. Likewise we need the moon to sustain all kinds of herbs and their distinct tastes and properties. The plants and their blossoming depend significantly on the moon. Paddy seeds are selectively exposed to moon-rays for improving their quality. Life forms need sunlight and heat. For herbal life likewise, moonlight is indispensable. Krishna says the moon derives its nourishing property from the inmost Self, as does the sun its brilliance.

Manifesting as fire of life (Vaiśvānara) in the bodies of creatures, I (the Supreme) conjunct with prāṇa and apāna (the vital forces) and digest the four-fold food.

It is interesting to note how Krishna gives minute details of biological functions in our body, connecting them with the presence and potential of the Supreme. The Supreme, as Vaiśvānara (fire of life) residing in the body of creatures, associated with prāṇa and apāna (the incoming and outgoing breaths), digests the food. Heartbeat and bellowing of lungs are incessant functions, which cannot stop or relax at all. These give rise to many simultaneous functions, especially in the alimentary canal. The intestines go on with their peristaltic movement, resulting in digestion of food, its absorption and assimilation. i) Bhakshya, chewn and eaten, ii) bhojya, swallowed with the tongue, iii) choshya, to be sucked in, and iv) lehya, to be licked, are the four types of food that nourish our body. Whatever the mouth receives reaches the stomach, passes through intestines, gets digested and absorbed into the system, and the waste gets excreted. All these functions are completed by the power of the Supreme manifesting through prāṇa and apāna.

I (as the Supreme) am embedded in the heart of all. Memory, wisdom and forgetfulness are from Me. I alone am to be known by all the Vedas. I am indeed the knower of the Vedas and the author of Vedanta.

Right from the beginning Krishna's focus has been the Self, the imperishable sentient presence in the body. He identified himself, Arjuna and all else with this inmost Presence (2.12), showing how immutable, unaffected and unconquerable It is, by Its very nature. The Self is equally present everywhere and in everything. Thus omnipresence and indwelling-ness are Its special characteristics, which go together. On this basis, Krishna points that the Self cannot be missed any time by the earnest enquirer. True discrimination cannot but lodge the seeker in the Self, wherever he is and whatever he does. Kṛṣṇa has already stated that the Self is the brilliance of the sun and the moon alike. It is the prāṇa and apāna, the life forces. It is also present in the digestive process. All these are bodily functions. He now takes up the non-physical cognitive functions like experience, knowledge and memory. He also stresses that the Supreme itself is forgetfulness as well. A very great revelation indeed! Everyone tries hard to remember matters. But what is memory, except in the background of forgetfulness? You need to remember something only if there is a chance of forgetting. When forgetfulness is removed, memory is restored. Remembering something implies its presence in memory. Equally so, when you forget something, you are aware of the absence of its presence in your memory. Thus both forgetfulness and memory, being complementary, imply a presence. How true is Kṛṣṇa’s statement that both memory and forgetfulness arise from the Supreme, are sourced by the Supreme! If you channelize your thoughts in these lines, you will never get distanced from the Self, the Supreme, even for a fraction of a second. For, memory and forgetfulness immerse you alike in the Supreme.

As I (the supreme Purusha) transcend the perishable existence and the imperishable (jīva), hence I am famous in the Vedas and the world as Purushottama.

Purusha is a word indicating the Supreme, the very source of all existence, creation. It means the one that inheres in a body. Humans are also called purushas as each of them resides in a body, calling it ‘my body, my residence’. Earlier Krishna described the nine-gated city, the body, in which resides the indweller (5.13). Here he describes prakṛti itself consisting of the perishable, kshara purusha, and imperishable, akshara purusha, permeating the body and the world. He also speaks of the still greater aspect, the Purushottama, the one from whom prakṛti’s guṇas begin to manifest. It is beyond the avyākṛta, unmanifest nature. It permeates all the three worlds of wakefulness, sleep and dream. It is the controller and guide for everything within the three states. Hence, in the Vedas and the world it is famous as Purushottama, dwelling in the body and extending beyond.

O Bhārata (Arjuna), overcoming delusion, he, the knower of all, worships Me thus as the Purushottama, he, the knower of all, worships Me through all his thoughts, attitudes and actions.

The revelation is par supreme. What the seeker has to know is only his own composite personality. This makes the focus clear, precise. He has nothing different or distant from himself, to know or gain. Body is but the matter-energy sheath. Within it are mind, intelligence and ego, the expressional notes of sentience. They are but the display of the indwelling Spirit, the Consciousness. Revealing the body and senses, then the mind, intelligence and ego, 'I' inheres as the substratum for all these. To know It well is to know everything and all, as It alone reveals everything through the mind. There is nothing besides the inner mind-display. And at no time is the seeker disconnected from his own within. This understanding makes him an all-knower. His worship becomes comprehensive.

Thus is revealed to you by Me, this greatest secret of all śāstras, O sinless soul. Understanding this, O Bhārata, does one become wise and fulfilled.

Krishna says he has revealed to Arjuna the entire secret contained in all śāstras. Śāstra is a rational, systematic presentation of its subject, evaluating the good and the bad, the merits and the demerits of what it exposes. Strength and purpose of the śāstras consist in enlightening the reader or listener. Krishna has covered the entire complex nature, display of which is the endless Creation. He has also revealed that the measure and magnitude the senses reveal have their locus within one's own body, in the mind and the intelligence. Outwardness and grossness are but notional. A proper knowledge about this will show that the mind within is the sole source of every experience and expression. This, in turn, leads to the subsidence of desires, hatred and fear, making the seeker free, natural and harmonious. One becomes an all-worshipper, his worship including all his attitudes and goals alike. With the dawning of wisdom he fulfils the purpose of life.