Bhagavad Gita Chapter 15, Verse 1

श्रीभगवानुवाच | ऊर्ध्वमूलमधःशाखमश्वत्थं प्राहुरव्ययम् | छन्दांसि यस्य पर्णानि यस्तं वेद स वेदवित् ||

śrī-bhagavān uvāca ūrdhva-mūlam adhaḥ-śākham aśvatthaṁ prāhur avyayam chandāṁsi yasya parṇāni yas taṁ veda sa veda-vit

The Blessed Lord said: They speak of an imperishable banyan tree with its roots upward and branches downward, whose leaves are the Vedic hymns. One who knows this tree is the knower of the Vedas.

Krishna introduces one of the Gita's most powerful metaphors: the material world as an upside-down tree. 'Ūrdhva-mūlam adhaḥ-śākham'—roots upward, branches downward. This reverses normal perception. The tree is 'aśvatthaṁ avyayam'—imperishable, eternal. But it's not eternal in a positive sense—it's the eternal cycle of material existence that traps you. 'Chandāṁsi yasya parṇāni'—the Vedas are its leaves. This means the Vedas describe the material world, its laws, and its entanglements. 'Yas taṁ veda sa veda-vit'—who knows this tree knows the Vedas. But merely knowing isn't enough—you must cut it. The tree represents everything that binds you: desires, attachments, karma, the complex web of material existence. Its roots are above because they're in the spiritual realm, but the branches spread downward into the material world, entangling you. To be free, you must understand this tree and then cut it with detachment.