Krishna says, "Just as one sun illuminates the entire solar system, the individual soul illuminates the entire body" (13.34). The soul is needed to bring life to the body which is like electricity bringing life to appliances.

The thirteenth chapter of the Gita is titled ' 𝙠𝙨𝙝𝙚𝙩𝙧𝙖’ (field) 𝙠𝙨𝙝𝙚𝙩𝙧𝙖𝙜𝙣𝙖 (knower of field) 𝙫𝙞𝙗𝙝𝙖𝙟𝙖𝙣 𝙮𝙤𝙜𝙖 ' where Krishna clarifies that the physical body is called 𝙠𝙨𝙝𝙚𝙩𝙧𝙖 whose attributes include 𝙖𝙝𝙖𝙣𝙠𝙖𝙖𝙧 (I am doer), intellect (𝙗𝙪𝙙𝙙𝙝𝙞) , mind, ten senses, five objects of the senses, desire, hatred, pleasure, pain, skeleton and consciousness (𝙘𝙝𝙚𝙩𝙖𝙣𝙖) . The knower of 𝙠𝙨𝙝𝙚𝙩𝙧𝙖 is called 𝙠𝙨𝙝𝙚𝙩𝙧𝙖𝙜𝙣𝙖.

Krishna mentions about twenty aspects of knowledge and he keeps humility at the beginning indicating that it is a virtue rather than a weakness. Other aspects of knowledge include forgiveness, self-control, dispassion (𝙫𝙖𝙞𝙧𝙖𝙜𝙮𝙖𝙢) towards sense objects, absence of 𝙖𝙝𝙖𝙣𝙠𝙖𝙖𝙧, non-attachment and eternal equanimity towards desirable and undesirable circumstances. Krishna further explains about the object of this knowledge. One enjoys immortality once one attains 'that' which is to be known. It is neither existent (𝙨𝙖𝙩) nor nonexistent (𝙖𝙨𝙖𝙩) and dwells in the world enveloping all. He gives a path to attain 'that' through meditation (𝙙𝙝𝙮𝙖𝙣) , awareness, 𝙠𝙖𝙧𝙢𝙖 or listening to the saints.

Krishna talks about 𝙥𝙧𝙖𝙠𝙧𝙞𝙩𝙞 (nature) which is responsible for cause and effect; and 𝙥𝙪𝙧𝙪𝙨𝙝 (spirit) who is responsible for the experience of 𝙨𝙪𝙠𝙝 (pleasure) and 𝙙𝙪𝙠𝙝 (pain) through subjective interpretation. Both are 𝙖𝙣𝙖𝙖𝙙𝙞 (beginning less).

Krishna concludes the thirteenth chapter of the Bhagavad Gita and says, "Those who perceive with the eyes of knowledge the difference between the 𝙠𝙨𝙝𝙚𝙩𝙧𝙖 and the 𝙠𝙨𝙝𝙚𝙩𝙧𝙖𝙜𝙣𝙖, and the process of 𝙥𝙧𝙖𝙠𝙧𝙞𝙩𝙞 𝙢𝙤𝙠𝙨𝙝𝙖𝙢 (ultimate freedom from nature), attain the 𝙥𝙖𝙧𝙖𝙢 (supreme)"(13.35). This is an assurance from Lord Krishna that one reaches the eternal state once we attain existential understanding of 𝙠𝙨𝙝𝙚𝙩𝙧𝙖 and 𝙠𝙨𝙝𝙚𝙩𝙧𝙖𝙜𝙣𝙖 .