A central message of the Bhagavad Gita is that of the Kshetra (the field) and the Kshetraajna (the knower of the field)
The importance placed on this can be seen in the verses in Chapter 13 of the Gita.
Kshetra, refers to both the external field of materiality as well as the internal field of the body-mind complex. The external field would include all manifested phenomenal existence, which would include all the objects of sensory perception. That is to say whatever we identify with our everyday sense of ‘this is the world I live in’ is included in the ‘external’ field of Kshetra.
The ‘internal’ field of Kshetra includes physical, mental and emotional components of the body-mind complex.
The range of sensations, conceptual thought processes and patterns as well as the range of emotions are included in the word Kshetra.
The Kshetrajna (‘jna’ signifies knowing), would be the knower of the external phenomenal objects and the internal psycho physical realms.
Ksehtrajna is a quality of knowing which is beyond any conceptual thought process.
Once there is a ‘seeing’ or ‘knowing’ of a particular thought or emotion, there is this understanding that on a deeper level we are not that what is now seen and this results in a shift in what one would otherwise identify oneself as.
A natural progression of inquiring into the external and internal fields would be the seeing of their inter-connectedness and an understanding of their inherent non dual relation, that is diminishing of the gap between what one would otherwise construe as ‘external’ and ‘internal’.
In other words, inquiring into Kshetra includes inquiring into all subject-object conceptions, that is the sense of ‘this is who I am and this is the world I live in’ or ‘this is me’ and ‘this is you’.
The Kshetrajna, the knower of the Kshetra, then is a quality of consciousness beyond subject-object conceptions and reflects our deeper non conceptual nature. This consciousness is also called the non dual/absolute/timeless consciousness and is another name for Brahman.
Since ‘Lord Krishna’ says that he is no other than the Kshetrajna, we can see him as this quality of consciousness.
The Kshetrajna is the one from whom all the modes of external and internal consciousness arise from and return to.
That is a primordial consciousness which is fundamentally not affected by any sense of personhood nor from any time bound experience but rather from which the very sense of individual personhood along with the sense of time arise from and to which they return to.
We can see that to be interested in the message of the Gita is then an interest and a willingness to examine, analyse and to de-construct our fundamental belief (or rather mis-belief) in who we are and the world in which we live in.
In the language of the Buddha, the Kshetrajna can be compared with his depiction of ultimate reality and the Ksehtra with conditioned reality.