Krishna says, "O Arjuna, this body is termed as the Kshetra and him who knows it, the sages discerning the truth about is - both are referred to as knower of this Kshetra or Kshetrajana."
(Chap 13 - verse 1)
"Know Myself to be the Kshetrajana (individual soul) also in all Kshetras, Arjuna. It is the knowledge of Kshetra and Kshetrajana which I consider as Wisdom." (Chap 13 - verse 2)
"What that Kshetra is and what it is like, and also what are its evolutes, again, whence is what and also finally who that Kshetrajana is and what his glory - hear all this from Me in a nutshell."
(Chap 13 - verse 3)
The truth about the Kshetra and Ksetrajana has been expounded by the seers in manifold ways; again, it has been separately stated in different Vedic chants and also in the conclusive and reasoned texts of Brahmasutras.(Chap 13 - verse 4)