भूमिरापोऽनलो वायुः खं मनो बुद्धिरेव च । अहङ्कार इतीयं मे भिन्ना प्रकृतिरष्टधा ॥
bhūmirāpo'nalo vāyuḥ khaṃ mano buddhireva ca | ahaṅkāra itīyaṃ me bhinnā prakṛtiraṣṭadhā ||
Translation
Earth, water, fire, air, space, mind, intellect, and ego-sense — these are My eightfold divided lower nature (prakriti).
Interpretation
Krishna begins revealing his two natures. The lower nature (apara prakriti) is the entirety of the material and psychological world: five physical elements (earth, water, fire, air, space/ether) plus three inner instruments (mind — manas, intellect — buddhi, ego-sense — ahankara). This is the world as we normally experience it — the complete catalogue of what we call 'reality' in the ordinary sense. But this is only the lower nature.