Gita : Ch-13. Slo-3.

Srimad  Bhagavad-Gita :

Chapter-13. ( Kshetra-kshetrajna-vibhaga-yogam )

Slokam-3. ( arjuna!  you should understand that I am also the knower in all bodies, and to understand this body and its owner is called knowledge. This  is My opinion.)

kshetrajnam  capi  mam  viddhi  sarvakshetreshu  bharata,

kshetrakshetrajnayorjnanam  yattat  jnanam  matam  mama.

bhatata!   sarvakshetreshu  api  =  arjuna!  in  all  Kshetram-s  (bodies);

mam  kshetrajnam  viddhi  =  know  I  am  the  Kshetrahnan;

kshetrakshetrajnayo  =  about  Kshetrajnan;

yat  jnanam  tat  jnanam  =  knowledge  is  jnanam;

(iti)  mama  matam  =  this  is  opinion.

Discussion -

In  the  previous  slokam-s  after  explaining  about  'Kshetram  and  Kshetrajnan'  here  in  this  slokam,  Lord  declares :

"In  all  Kshetram-s  I  am  the  Kshetrajnan."

Then  if  it  is  one  Kshetrjnan  in  all  kshetram-s,  what  is  the  explanation  for  this  world's  diversity  of  its  people ( Kshetram-s )?

Anatma-vastu-s  manifest  many  only;  their  tattvam  the  one  and  only  Paramatma  itself.

It  is  not  different  from  one,  but  it  is  sva-svrupam  of  each  Sadhakan,  and  he  must  realise  this  by  experience.

That  is  Me  only  ( Soham )  and  this  'anubhuti' itself  'Atma-sakshatkam'.

Therefore,  Lord  declares :  "in  Sarva - Kshetram-s  the  insider,  i.e,  the inner  chaithanyam  is  Me,  the 'Kshetrajnan."

Lord  now  in  the  state  of  'Yogarudan'  i,e,  one  should  not  see  Paramatma  different  / away  from  him,  but  in  him   itself.

"Electricity  can  claim  that  it blazes  in   all  bulbs  all over  the  world!"

After  telling  about  the  above  details,  Lord  says : that  'Jnanam' is  is  the  knowledge  of  this  tattvam  i.e,  "Khetram  and  Kshetrajnan".

Body-s  etc  are  not  permanent,  should  be  deposited  back  to  Panch-bhuta-s.

But  Atma  is  not  perishable,  but goes  back  to  the Paramatma.

And  this  awareness  /  knowledge  is  'Jnanam' ( Atmeeyam).    
Next : Slokam-4.
To be continued  .....