Bhagwad Gita
Chapter 15, Verse 1
श्री भगवानुवाचऊर्ध्वमूलमधःशाखमश्वत्थं प्राहुरव्ययम्।छन्दांसि यस्य पर्णानि यस्तं वेद स वेदवित्।।15.1।।
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.