Verse
श्रीभगवानुवाच:ऊर्ध्वमूलमधःशाखम् अश्वत्थं प्राहुरव्ययम् ।छन्दांसि यस्य पर्णानि यस्तं वेद स वेदवित् ॥
The Blessed Lord said: With its original source above (in the Eternal), its branches stretching below, the Ashwattha is said to be eternal and imperishable; the leaves of it are the hymns of the Veda; he who knows it is the Veda-knower.
Gītā 15·1