Srimad Bhagavad-Gita :
Chapter-13. ( Kshetra-kshetrajna-vibhaga-yogam )
Slokam-1. ( Arjuna question to Lord Sri Krishna ) -
(Arjuna said: O Lord, I wish to know about prakrti [nature], Purusha [the experiencer], and the field and the knower of the field, and of knowledge and the end of knowledge. )
prakrtim purusham caiva kshetram kshetragjnameva ca,
etadveditumicchami jnanam jneyam ca kesava.
arjuna uvaca = Arjuna said;
kesava! = O Lord;
prakrtim purusham ca eva = nature, and the experiencer;
kshetram kshetragjnam ca eva = kshetram (body), and kshetragjnan ( jivatma );
jnanam jneyam ca etat = jnanam ( knowledge ), jneyam ( object of the knowledge, all about these;
veditum icchami = I wish to know.
Lord Krishna explains that while in a physical body the jiva or embodied being believes they are that body, thinking I am a man, I am a demigod, I am a female, I am famous, I am powerful, etc. all of which are distinctly different form the atma or eternal soul.
The physical body is that which the spiritually intelligent assert as the ksetra or field of enjoyment.
One who has the realisation of the jiva being part of an aggregate whole composed of divisible parts being the physical body, the subtle body and the atma.
One who has the understanding that I know this body and instead of the mentality that I am this body.
One who is cognisant of these things and realises what the atma actually is factually asserted as being ksetrajna or the knower of the field.
It can be said that when cognition of objects external to the physical body arises the conception of I am my human body who sees for example this house before me, implying that the one who sees thinks the atma is inseparable from the physical body and not that the atma is totally independent of the physical and subtle bodies.
Subsequently when one has achieved atma tattva or realisation of the soul and experienced its spiritual existence then one will be cognisant of their physical body merely as a house within which the atma inhabits.
To perceive a house as external from the physical body is the same as perceiving the atma as external from the physical body for one who is realised.
One who is cognisant of this reality sees the atma as a distinct entity separate from the physical and subtle bodies.
To be continued .....