Shri Krishna begins the chapter by describing what is meant by the field and the knower of the field, kshetra and kshetrajnya. He reminds us that this knowledge is not something new, that it has come directly from the Vedas and the Brahma Sutras. He then describes the field in detail by listing its modifications such as the great elements, the ego, the senses and so on. A list of attributes or qualities that are needed in order to escape the influence of the field is given. These qualities include humility, lack of arrogance and so on. These qualities are termed as “jnyaanam” or means of knowledge.
The topic of the supreme self, brahman, the knower of the field or kshetrajnya, is taken up next. The “sat” or existence aspect of brahman is indicated first with attributes such as hands, legs and so on. It is then indicated with negation of those same attributes, following the “adhyaaropa apavaada” technique used in Vedanta. Brahman, which can never become an object of our knowledge, is explained through a series of paradoxes – it is near, yet it is far and so on. The “chit” or awareness aspect of brahman is also highlighted using the phrase “it is the light of all lights”.
The field and its knower are now explained from the point of view of the individualized self, jeeva by using the terminology of Purusha and Prakriti. Shri Krishna first defines these terms, points out their beginningless nature, and also points out how they become the cause of enjoyership and doership respectively. The fall of the immaculate supreme self is explained by the apparent relationship of Purusha and Prakriti due to ignorance of our true nature as the supreme self that resides as Ishvara in all bodies. Release from this ignorance leads to liberation.
In order to get to a stage where we can discriminate or distinguish between the field and its knower, we have to go through a curriculum of saadhanaa or spiritual practice. Shri Krishna provides this roadmap of steps as karma, bhakti, raaja and saankhya yoga. The key thing, however, is to orient or attach ourselves to the imperishable Ishvara, and to detach ourselves from identification with Prakriti, which is the storehouse of all action and diversity.
Shri Krishna concludes the chapter with two illustrations highlighting the existence and awareness, the sat and chit aspects of the supreme self. The analogy of space is used to illustrate the all-pervading, unattached, untainted and singular nature of the supreme self. The analogy of the sun is used to illustrate the knowledge, awareness and non-acting nature of the supreme self. The chapter ends by asserting that the fruit of knowing the true nature of the supreme self is moksha or liberation.