Shree Bhagavaan uvaacha:
oordhvamoolamadhahashaakhamashvattham praahuravyayam |
chhandaamsi yasya parnaani yastam veda sa vedavita || 1 ||

Shree Bhagavaan said:
With roots above and branches below, the Ashvattha tree is said to be imperishable, with the Vedas as its leaves. He who knows this, knows the Vedas.

oordhvamoolam : roots above
adhahashaakham : branches below
ashvattham : Ashvattha tree
praahuhu : is said
avyayam : imperishable
chhandaamsi : Vedas
yasya : of whose
parnaani : leaves
yaha : who
tam : that
veda : knows
sahe : he
vedavita : Vedas
Shri Krishna begins the fifteenth chapter describing an unusual sort of tree. It is “oordhvamoolam adhahashaakham”. It is upside down, with roots above and branches below. It is not as unusual as it sounds, because we encounter several trees that are inverted in our lives. A family tree, the map of an organization with the CEO on top, a decision tree in management sciences, all of these trees are upside down, with their root on top and branches below.
Such inverted trees have some interesting characteristics. The farther away one goes from the root, the greater is the loss of the substance or the essence. A junior employee has far less power than the CEO in an org chart, for instance. Also, these trees are never static. They keep changing. Hence, the tree described in this illustration is called “ashvattha”, which means not lasting for long. This is also the name of the tree known as ficus religiosa, or the Peepul tree in India.
Now, let us examine the metaphors used in this illustration. The root of this tree is Ishvara, the saguna brahman, the eternal essence with form. Its branches have evolved from Ishvara, and are nothing but the hardening of Prakriti, the hardening of the three gunas due to their permutations and combinations. The process of the creation of the universe has been explained in detail in prior chapters. It is similar to a tender, subtle sapling hardening into a robust tree as it grows over time. It is termed as avyayam or imperishable because it is permanent after its reality has been ascertained, like the illusion of the blue sky. Even when we come to know that the sky is not really blue, but just looks that way, we still perceive the illusion.
In any complex system, there are rules that tell how what to do and what not to do. The Vedas are the rules of this universe, and are metaphorically represented as the leaves of this ashvattha tree. Just like there are rules on how to get promoted in a corporation, there are rules in the Vedas that give us instructions on how to act in life, and how not to commit sins or errors. They are the storehouse of knowledge and actions needed to thrive in this world. One who knows the functioning of the universe in this manner, one who knows how to get to the source which is Ishvara, needs to know nothing else.
We now come to the fundamental question. Why has Shri Krishna started talking about this tree now? It is to cultivate dispassion or vairagya in us. Even a tinge of attachment to the world can derail our spiritual progress. Over the next few shlokas, we will learn more about this tree so that we can understand our entanglement in it, and consequently, learn how to release ourselves from it through dispassion.