The Gita introduces and describes the concept of a supreme Person, the Purushottama, who holds within his Being, all of the creation, while not being bound by the forms or beings of the creation; and who is also the unmanifest, the unmoving; however, the Purushottama goes beyond both of these aspects, so that he is not defined, limited or circumscribed by any description we choose to place on him with our limited mental capacity of conceptualisation and expression in language. The Upanishads make it clear that the Eternal Brahman is “not this, not that” and that neither mind nor speech can limit the Reality. We therefore cannot attach ourselves to either the Akshara Purusha (unmoving Self, unattached to the world) or the Kshara Purusha (the consciousness that participates in the manifested universe) to gain any true understanding of existence. The Purushottama, then provides a concept which exceeds both aspects and all limits, and is the ultimate Creator, Lord, and Enjoyer of the universe.
Sri Aurobindo describes the nature of the Purushottama: “…eternal beyond all manifestation, infinite beyond all limitation By Time or Space or Causality or any of his numberless qualities and features….He is the supreme ineffable Brahman, he is impersonal self, he is all personal existences. Spirit here and life and matter, soul and Nature and the works of Nature are aspects and movements of his infinite and eternal existence. He is the supreme transcendent Spirit and all comes into manifestation from him and are his forms and his self-powers. As the one self he is here all-pervasive and equal and impersonal in man and animal and thing and object and every force of Nature. He is the supreme Soul and all souls are tireless flames of this one Soul. All living beings are in their spiritual personality deathless portions of the one Person or Purusha. He is the eternal Master of all manifested existence, Lord of the worlds and their creatures….He is in all and all are in him; he has become all and yet too he is above all and not limited by his creations. He is the transcendent Divine; he descends as the Avatar; he is manifest by his power in the Vibhuti; he is the Godhead secret in every human being.”
Sri Aurobindo, Essays on the Gita, Second Series, Part II, Chapter 24, The Message of the Gita, pp. 558-559