Lord Krishna said: Listen again, O Arjuna (Mahābāhu), my ultimate words. I tell you these, because I am fond of you and desirous of your welfare.
Krishna, without any request from Arjuna, begins to say something besides whatever he already described (chapter 7) about the complex cyclic creation process, including birth, emergence, existence, expression and extinction. About the inexorable prakrti surrounding and permeating the whole Creation.
The aggregate of panca-bhutas, mind, intelligence and ego, brings about this ceaseless cyclic process of creation, preservation and destruction. It is the interplay of the three qualities – sattva, rajas and tamas – in the Self that remains the sole substratum for everything.
A proper knowledge in this regard will alone make one’s mind peaceful and intelligence stable, enabling his worldly interactions light, poised and effective.