Bhagavan Shri Krishna said: It has been told that there is an imperishable banyan tree that has its roots above, its branches below and its leaves are the Vedic mantras. One who knows this tree is the knower of the Vedas.
Bhagavad Gita - Chapter 15 - Purushottama Yoga - The Yoga of the Supreme Person
Some branches of this tree spread upwards and others grow downwards, nourished by the modes of nature. The twigs on the tree are the sense-objects, and the roots that extend downwards reach the human plane and are the cause of the binding activities of human society.
The form of this tree cannot be perceived in this world. Indeed, none can fully comprehend where the tree begins, where it ends, or where its foundation lies. One must cut down this strong-rooted banyan tree with the weapon of detachment and search out that place from which, once having gone, one never returns. One must take shelter of the Supreme Person, from whom all things have originated from time immemorial.
Free from pride, illusion and bad association, dedicated to spiritual pursuits, forsaking lust, unburdened by the dualities of happiness and distress – such wise persons attain the eternal realm.
My Supreme Abode is not illumined by sun, moon or fire. Once attaining that abode, one never returns.
The living beings of this world are My eternal particles. These living beings struggle with the five senses and the mind, which is the sixth sense within.
Whenever the individual being, the master of the body, accepts or gives up a material body, his senses and mind follow him to the next birth, just as the wind carries a fragrance from its source.
The living beings enjoy the objects of the senses and preside over the ears, eyes, skin, tongue, nose and the mind.
Those who are ignorant can neither understand when the individual unit of consciousness is leaving the body, when it is residing within the body, or when it is enjoying the objects of the senses. Only those with the eyes of knowledge can perceive this.
The sincere yogi sees the atma situated within, but those who lack true understanding and self-control cannot perceive the atma no matter how hard they try.