"The Blessed Lord said: There is a banyan tree which has its roots upward and its branches down and whose leaves are the Vedic hymns. One who knows this tree is the knower of the Vedas.

Bhagavad-gita 15:1

Purport: After the discussion of the importance of bhakti-yoga, one may question, "What about the Vedas?" It is explained in this chapter that the purpose of Vedic study is to understand Krsna. Therefore one who is in Krsna consciousness, who is engaged in devotional service, already knows the Vedas. The entanglement of this material world is compared here to a banyan tree. For one who is engaged in fruitive activities, there is no end to the banyan tree. He wanders from one branch to another, to another, to another. The tree of this material world has no end, and for one who is attached to this tree, there is no possibility of liberation. The Vedic hymns, meant for elevating oneself, are called the leaves of this tree. This tree's roots grow upward because they begin from where Brahma is located, the topmost planet of this universe. If one can understand this indestructible tree of illusion, then one can get out of it.

This process of extrication should be understood. In the previous chapters it has been explained that there are many processes by which to get out of the material entanglement. And, up to the Thirteenth Chapter, we have seen that devotional service to the Supreme Lord is the best way. Now, the basic principle of devotional service is detachment from material activities and attachment to the transcendental service of the Lord. The process of breaking attachment to the material world is discussed in the beginning of this chapter. The root of this material existence grows upward. This means that it begins from the total material substance, from the topmost planet of the universe. From there, the whole universe is expanded, with so many branches, representing the various planetary systems. The fruits represent the results of the living entities' activities, namely, religion, economic development, sense gratification and liberation.

Now, there is no ready experience in this world of a tree situated with its branches down and its roots upward, but there is such a thing. That tree can be found beside a reservoir of water. We can see that the trees on the bank reflect upon the water with their branches down and roots up. In other words, the tree of this material world is only a reflection of the real tree of the spiritual world. This reflection of the spiritual world is situated on desire, just as a tree's reflection is situated on water. Desire is the cause of things being situated in this reflected material light. One who wants to get out of this material existence must know this tree thoroughly through analytical study. Then he can cut off his relationship with it.

This tree, being the reflection of the real tree, is an exact replica. Everything is there in the spiritual world. The impersonalists take Brahma to be the root of this material tree, and from the root, according to Sankhya philosophy, come prakrti, purusa, then the three gunas, then the five gross elements (panca-maha-bhuta), then the ten senses (dasendriya), mind, etc. In this way they divide up the whole material world into twenty-four elements. If Brahma is the center of all manifestations, then this material world is a manifestation of the center by 180 degrees, and the other 180 degrees constitute the spiritual world. The material world is the perverted reflection, so the spiritual world must have the same variegatedness, but in reality. The prakrti is the external energy of the Supreme Lord, and the purusa is the Supreme Lord Himself, and that is explained in Bhagavad-gita. Since this manifestation is material, it is temporary. A reflection is temporary, for it is sometimes seen and sometimes not seen. But the origin from whence the reflection is reflected is eternal. The material reflection of the real tree has to be cut off. When it is said that a person knows the Vedas, it is assumed that he knows how to cut off attachment to this material world. If one knows that process, he actually knows the Vedas. One who is attracted by the ritualistic formulas of the Vedas is attracted by the beautiful green leaves of the tree. He does not exactly know the purpose of the Vedas. The purpose of the Vedas, as disclosed by the Personality of Godhead Himself, is to cut down this reflected tree and attain the real tree of the spiritual world.

"The branches of this tree extend downward and upward, nourished by the three modes of material nature. The twigs are the objects of the senses. This tree also has roots going down, and these are bound to the fruitive actions of human society."

Bhagavad-gita 15:2

Purport: The description of the banyan tree is further explained here. Its branches spread in all directions. In the lower parts, there are variegated manifestations of living entities such as human beings, animals, horses, cows, dogs, cats, etc. These are situated on the lower parts of the branches, whereas on the upper parts are higher forms of living entities: the demigods, Gandharvas and many other higher species of life. As a tree is nourished by water, so this tree is nourished by the three modes of material nature. Sometimes we find that a tract of land is barren for want of sufficient water, and sometimes a tract is very green; similarly, where the modes of material nature are proportionately greater in quantity, the different species of life are manifest in that proportion accordingly.

The twigs of the tree are considered to be the sense objects. By development of the different modes of nature, we develop different senses, and, by the senses, we enjoy different varieties of sense objects. The source of the senses--the ears, the nose, eyes, etc.--is considered to be the upper twigs, tuned to the enjoyment of different sense objects. The leaves are sound, form, touch--the sense objects. The roots, which are subsidiary, are the by-products of different varieties of suffering and sense enjoyment. Thus we develop attachment and aversion. The tendencies toward piety and impiety are considered to be the secondary roots, spreading in all directions. The real root is from Brahmaloka, and the other roots are in the human planetary systems. After one enjoys the results of virtuous activities in the upper planetary systems, he comes down to this earth and renews his karma, or fruitive activities for promotion. This planet of human beings is considered the field of activities.

"The real form of this tree cannot be perceived in this world. No one can understand where it ends, where it begins, or where its foundation is. But with determination one must cut down this tree with the weapon of detachment. So doing, one must seek that place from which, having once gone, one never returns, and there surrender to that Supreme Personality of Godhead from whom everything has began and in whom everything is abiding since time immemorial.

Bhagavad-gita 15:3

Purport: It is now clearly stated that the real form of this banyan tree cannot be understood in this material world. Since the root is upwards, the extension of the real tree is at the other end. No one can see how far the tree extends, nor can one see the beginning of this tree. Yet one has to find out the cause. "I am the son of my father, my father is the son of such and such a person, etc." By searching in this way, one comes to Brahma, who is generated by the Garbhodakasayi Visnu. Finally, in this way, when one reaches the Supreme Personality of Godhead, that is the end of research work. One has to search out the origin of this tree, the Supreme Personality of Godhead, through the association of persons who are in knowledge of that Supreme Personality of Godhead. Then by understanding one becomes gradually detached from this false reflection of reality, and by knowledge one can cut off the connection and actually become situated in the real tree.

The word asanga is very important in this connection because the attachment for sense enjoyment and lording it over material nature is very strong. Therefore one must learn detachment by discussion of spiritual science based on authoritative scriptures, and one must hear from persons who are actually in knowledge. As a result of such discussion in the association of devotees, one comes to the Supreme Personality of Godhead. Then the first thing one must do is surrender to Him. The description of that place whence going no one returns to this false reflected tree is given here. The Supreme Personality of Godhead, Krsna, is the original root from whom everything has emanated. To gain favor of that Personality of Godhead, one has only to surrender, and this is a result of performing devotional service by hearing, chanting, etc. He is the cause of this extension of the material world. This has already been explained by the Lord Himself: aham sarvasya prabhavah, "I am the origin of everything." Therefore to get out of the entanglement of this strong banyan tree of material life, one must surrender to Krsna. As soon as one surrenders unto Krsna, he becomes detached automatically from this material extension.
 

Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.