Lord Krishna said: Arjuna, this body is termed as the feld (Kshetra) and he who knows it is called the knower of the field (Kshetrajana) by the sages discerning the truth about both. Know myself to be the kshetrajana (individual soul) in all the kshetras (felds), Arjuna. And it is the knowledge of the field (kshetra) and knower (kshetrajana) (i.e., of matter with its evolutes and the spirit) which I consider as true knowledge.
Absence of pride, non-violence, uprightness of speech and mind, absence of egotism, equipoise of mind both in favourable and unfavourable circumstances, constancy in self-knowledge and seeing god as the object of true knowledge, all this is declared as knowledge and what is contrary to this is called ignorance. I shall speak to you at length about that which ought to be known and knowing which one attains supreme bliss. That supreme brahma who is the lord of the two beginning-less entities, prakriti and jiva, is said to be neither sat (being) nor asat (non-being). It has hands and feet on all sides, eyes, head and mouth in all directions and ears all-round; for it stands pervading all in the universe. Though perceiving all sense-objects, it is really speaking devoid of all senses. Though unattached, it is the sustainer of all nonetheless and though attribute-less, it is the enjoyer of gunas, the three modes of prakriti. That supreme brahma is said to be the light of all lights and entirely beyond maya. And that godhead which is knowledge itself worth knowing and worth attaining through real wisdom is the sustainer of beings (as vishnu), the destroyer (as rudra) and the creator of all (as brahma).
Prakriti is said to be responsible for bringing forth the evolutes and the instruments while the individual soul is declared to be responsible for the experience of joys and sorrows. It is attachment with these gunas that is responsible for the birth of this soul in good and evil wombs. He who thus knows the purusha (spirit) and prakriti (nature) together with the gunas even though performing his duties in every-way is not born again. Some by meditation behold the supreme spirit in the heart with the help of their refined and sharp intellect while others realise it through the discipline of knowledge and still others through the discipline of action, i.e. karmayoga.
He alone truly sees who sees the supreme as imperishable and abiding equally in all perishable beings both animate and inanimate. He who sees that all actions are performed in every-way by nature (prakriti) and the self as the non-doer, he alone verily sees. Arjuna, as the one sun illumines this entire universe, so the one aatma (spirit) illumines the whole kshetra (field). Those who thus perceive with the eye of wisdom, the difference between the kshetra and kshetrajana and the phenomenon of liberation from prakriti with her evolutes reach the supreme eternal spirit or attains brahma.