B.G 15.01
श्रीभगवानुवाच
The auspicious Lord said:
ऊर्ध्वमूलमधःशाखं अश्वत्थं प्राहुरव्ययम्। छन्दांसि यस्य पर्णानि यस्तं वेद स वेदवित् ॥१॥
They speak of the imperishable peepul tree having its roots above and branches below. Its leaves are the Vedas, i.e. knowledge; he who knows it is the knower of the Vedas.
Gīta Tātparya 15.01
Here, the union of consciousness and matter is declared to be a tree. The earth, the deity, is like clay, the insentient. Lord Hari, due to the superiority of the roots, is remembered as having roots above. From there, the inferior - 'mahat aham', i.e. the great ego principle, intellect - joined with elements, emerged. The branches are the Vedic hymns, and the leaves represent desires and liberation.
त्रयोदशाध्यायोक्तं विविच्य दर्शयति-
It elaborates on the topics touched on in the thirteenth chapter (13.06).
"पृथङ्ग् मूलं हरिस्त्वस्य जगद्वृक्षस्य भूमिवत्। सत्त्वादियुक्ते चिदचित्प्रकृती मूलभागवत्॥ अत्रापि चिदचिद्योगो वृक्षवत् सम्प्रकीर्तितः। पृथिवी देवतावत् तद्धरिर्मृद्वदचेतना। उत्तमत्वात्तु मूलानामूर्ध्वमूलस्त्वयं स्मृतः। नीचास्ततो महदहम्बुद्धयो भूतसंयुताः। शाखाः छन्दांसि पर्णानि काममोक्षफले ह्यतः॥ ॥१॥"
"Lord Hari is the distinct root of the world tree. The earth, possessing qualities such as sattva, represents both the conscious and unconscious aspects of nature, being the divine root. Here, the union of consciousness and matter is declared to be a tree. The earth, the deity, is like clay, the insentient. Lord Hari, due to the superiority of the roots, is remembered as having roots above. From there, the inferior - 'mahat aham', i.e. the great ego principle, intellect - joined with elements, emerged. The branches are the Vedic hymns, and the leaves represent desires and liberation."