Chapter 7 · Knowledge and Realisation · Krishna said
Bhagavad Gita 7.4 — Eightfold nature
भूमिरापोऽनलो वायुः खं मनो बुद्धिरेव च। अहंकार इतीयं मे भिन्ना प्रकृतिरष्टधा ॥
bhūmirāpo'nalo vāyuḥ khaṃ mano buddhireva ca | ahaṃkāra itīyaṃ me bhinnā prakṛtiraṣṭadhā ||
Meaning
Earth, water, fire, air, space, mind, intellect and ego — these are the eight parts of my material nature.