Arjuna Asked
O Kesava, I desire to learn about the Prakriti and the Purusha, about the Field and the knower of the field, Wisdom and the object of the Wisdom.

The Resplendent Lord Said:
This body, O Arjuna, is called the Field (Kṣetra). One who knows it is called the ‘Knower of the Field’ (Kṣetrajña), by the enlightened ones.
(Or
This body, O Arjuna, is called the Field (Kṣetra). One who knows it is called the ‘Master of the Field’ (Kṣetrajña), by the enlightened ones.)
Know Me to be the knower of the field among all the fields O Arjuna. The knowledge of both the Field and its Knower is, in My view, the highest knowledge.

What is that field? What are its characteristics and modifications? From where does it arise? and what are its powers and limitations? Hear these from Me in brief.

It has been lauded by the sages in various ways, in various distinctive hymns of the Vedas, and also in the sound logic and conclusive arguments of the Brahma-sutras.

The five principle elements, the un=manifest Ahaṅkāra(the ego) and the intelligence, mind and the ten senses, the five sense objects. Desire, aversion, joy, sorrow, the aggregate organism (The body), concisous and determination are described in breif, along with the alterations in ksetra."

Humility; pridelessness; nonviolence; tolerance; simplicity; approaching a bona fide spiritual master; cleanliness; steadiness; self-control; renunciation of the objects of sense gratification; absence of false ego; the perception of the evil of birth, death, old age and disease; detachment; freedom from entanglement with children, wife, home and the rest; even-mindedness amid pleasant and unpleasant events; constant and unalloyed devotion to Me; aspiring to live in a solitary place; detachment from the general mass of people; accepting the importance of self-realization; and philosophical search for the Absolute Truth—all these I declare to be knowledge, and besides this whatever there may be is ignorance.

I shall declare that which has to be known, knowing which, one attains immortality — It is beginningless Brahman, to which I am superior; it is said to be neither being nor non-being.