The Field and Its Knower — Kshetra Kshetrajna Vibhaga Yoga
Chapter 13 of Bhagavad Gita by Vyasa
Arjuna said: Krishna! I fain would know what is this "field" That men do speak of, and the "knower" too; What is true knowledge, and what that which waits To be known; tell me, Keshava! the scope Of Nature and of Spirit, and of these The qualities, the powers, and the bounds.
Krishna said: This body, son of Kunti! is the Field; He who doth know it is the Knower named By sages who have searched the truth of things. I am that Knower, in all mortal frames, O Bharata! and knowledge of the Field And knowledge of the Knower of the Field I hold to be the sum of wisdom true.
What the Field is, and of what form, and whence It cometh, and what changes work in it, And by what power, and who that Knower is And what his might — learn these from Me! In brief This Field hath been described by ancient seers In many a Vedic chant, and in the songs Of holy Brahma-sutras, firmly set With reasons meet and subtleties of speech.

