"They (wise people) speak of the indestructible Peepul Tree (Ficus Religiosa) having its root above and branches below, whose leaves are the Vedas; he who knows it is a Veda-knower."
oordhwamoolam adhahshAkham ashwattham prAhuh awyayam chandAmsi yasya parnAni yah tam weda sah wedawit ||15.1||
The tree-of-multiplicity that has seemingly sprung forth from the Infinite Consciousness Divine, can be cut down by shifting our attention from the Tree to the Divine. Luckily, we who are educated in modern universities, have a similar use of the term "tree" in our history text books. The 'family trees' of kings and dynasties are, without any exception, shown as branching down from their ancestral 'source'. Similarly, the Tree-of-Samsara has its roots UP in the divine Consciousness. A tree holds itself up and gets nourished by its roots; similarly, the 'experiences' of change and 'experiencer' of them are all established in the Infinite and draw their sustenance from It alone.
For this tree-of-life "THE VEDAS THEMSELVES ARE THE LEAVES" -- Veda means 'knowledge'. Knowledge does bring forth a greater spirit of dynamism of life into the world.
Leaves are areas from which the water contents get evaporated in all trees, and this in its turn, creates the 'osmotic-pressure' in the roots and facilitates the roots to draw more quantity of nourishment from the earth. Cut down the leaves of the tree and its growth is immediately stunted; the larger the number of branches and leaves, the greater is the tree's dimension and growth. Where there is greater knowledge, there we are sure to find a greater flare of manifest-life.
HE WHO KNOWS IT, IS A KNOWER OF THE VEDA - He alone, who has realised not only the Aswatha-tree, but also the Higher, from which derives its existence, is the one who has filled his knowledge of the Vedas.
kim punah brAhmanAh punyAh bhaktAh rAjarshayah tathA anityam asukham lokam imam prApya bhajaswa mAm ||9.33||"How much more (easily) then the holy BRAHMINS, and devoted Royal saints (attain the goal). Having reached (obtained) this impermanent and joy- less world, do worship Me devoutly."
"HAVING ATTAINED THIS TRANSIENT AND JOYLESS WORLD, WORSHIP ME DEVOUTLY". This instruction to Arjuna is an instruction for all, since, in the Geeta if Lord Krishna represents the Self, Arjuna represents the confused man standing impotent against the challenges of life.
Life is lived in a field always constituted of objects, instruments, and mental moods. These three are ever in a state of change. Naturally, the flickering joys that come to us in life prove to be transient. And the intervals between any two experiences of joy are only FULL OF PAIN.
In tune with the positive and energising philosophy of optimism which the Geeta preaches, here Krishna declares the world to be a mere pit of sorrows, or a ditch of despair, or a mire of disappointments, or a field of joylessness (Asukham).
HAVING REACHED THIS WORLD, IMPERMANENT AND JOYLESS, Krishna advises Arjuna, that he must occupy himself in the worship of the Self.