Arjuna says:
O Kṛṣṇa, I desire to learn about the Self and about material nature, about the Field and its Knower, about knowledge and the goal of knowledge.

Lord Kṛṣṇa says:
This body, O Arjuna, is called the Field (kṣetra). One who has knowledge of this is called the ‘Knower of the Field’ (Kṣetrajña), by the enlightened ones.

And you should also understand that I am the Knower in all the Fields (as well as the inner Self), O Arjuna. In My view, this knowledge of the Field and (both) its Knowers is the highest knowledge.

Now, learn briefly from Me about the Field, what its nature is, what changes it undergoes, and which one of these comes from the other; also learn about the Knower of the Field and what His influence is.

This knowledge has been sung about by the sages in different ways, through various distinctive hymns of the Vedas. It has also been expressed through conclusive arguments in the Brahma-sūtras.

The principle elements, the ego, the intellect, the unmanifested, the ten senses, the five objects of the senses;

Attraction, aversion, pleasure and pain, the different faculties of the body, consciousness and one’s resolve, is briefly what composes the Field, and the various transformations it undergoes.

Being free from pride and deceit, humility, not harming, patience, integrity, service of the Master, purity, steadfastness and self-restraint;

Being detached from sense objects, rising above the sense of ego, seeing the misery of birth, death, old age and suffering;

Being without attachment and entanglement for son, wife, home and other such things; being equal-minded.

Having exclusive undeviating devotion to Me; being in solitude, having aversion from mundane society;

Having constant dedication to the path of Self-realisation and the goal of Truth – all of this should be considered ‘knowledge’ and everything else is ignorance.

I shall now explain what one must strive to know. Once this is realised, one attains immortality. That object of knowledge is beginning-less, it is Brahman which is dependent on Me; it is said to be neither existing nor non-existing.

Its hands and feet are everywhere; Its eyes, heads and faces are everywhere; Its ears are on all sides; and It exists, pervading all things.

It illumines the senses while remaining unconnected with the sense organs; It is detached and yet supports all; It is free from the guṇas and yet it experiences the guṇas.

It is inside and outside all beings; It is moving yet unmoving; It is so subtle that no one can comprehend It; It is far away, and yet so very near.

It is one and yet appears divided among living beings. That which must be known is the sustainer of all living beings. It devours them and brings them back into existence.

It is the light of all lights, beyond all darkness. It is knowledge itself, the object of knowledge and it can be attained through knowledge; It is present in the hearts of all beings.

In this way I have briefly explained the Field, knowledge and the object of knowledge. Upon realising this, My devotee attains that supreme relationship with Me.

Know that both material nature and the Self are without beginning, and all the transformations and guṇas arise from this material nature.

Nature is said to be the cause of all material causes and effects. The embodied soul, however, is said to be the cause of the various pleasures and pain experienced.

The Self which is situated in material nature experiences the effects of the different guṇas that arise from it. Entanglement to these guṇas is the cause of higher and lower births.

But within the body, supreme to the Self, there is another One that is called the Witness, the One who grants permission, the Supporter, the Enjoyer, the Great Lord, the Supersoul.

One who understands the spiritual and material nature along with its guṇas, is not born again, regardless of their situation.

Some perceive the Supersoul within themselves by meditation, others through gaining knowledge, and still others by karma-yoga.

Then there are those who do not follow any of these paths, but having heard teachings from others, they devote themselves to the Supreme and they too pass beyond death.

O Arjuna, whatever comes into being, be it moving or non-moving, only arises through a combination of the Field and the Knower of the Field.

Whoever sees the Supreme, dwelling alike in all bodies and never perishing despite the body doing so, truly sees.

One who sees the Supreme as equally existing in every place, does not degrade the Self by the mind. Therefore, they reach the highest goal.

One who sees that the Self does nothing and all action is done by material nature alone, truly sees.

When one understands that the difference and individuality of all beings is rooted and expanded from one Being, he realises Brahman.

O Arjuna, this Supreme Self is without beginning and is unchanging. Though It is in the body, It is free from the guṇas; It neither acts nor is It stained by action.

As all-pervading space is never affected by anything because of its subtle nature, so too the Self dwelling in the body is not tainted by the body.

As the Sun alone illumines this whole world, Arjuna, so too does the Knower of the Field illumine the whole Field.

Those with the eye of wisdom, who can perceive the difference between the Field and the Knowers of the Field, and how beings can be liberated from material nature — they attain the Supreme.