Bhagavad Gita Verse 23, Chapter 13

ya evam vetti purusham prakritim cha gunaih saha |
sarvathaa vartamaanopi na sa bhooyobhijaayate || 23 ||
 
He who thus knows Purusha and Prakriti, along with the gunaas, no matter what his conduct, is never born again.
 
yaha : he who
evam : thus
vetti : knows
purusham : Purusha
prakritim : Prakriti
cha : and
gunaih : gunaas
saha : along with
sarvathaa : whatever
vartamaanaha : conduct
api : no matter
na : not
saha : he
bhooyaha : again
abhijaayate : born
 
To better understand this shloka, let us quickly take a look at the theory of karma. It says that each of us comes with three types of karmas, which are unfulfilled desires that become seeds of future actions. Total karmas or “sanchita” karmas are the entire stock of our karmas. Present life karmas or “prarabdha” karmas are those karmas that are activated in our present life. Expected karmas or “agaami” karmas are those karmas that will be generated due to the results of actions in the present life. These karmas get added to our sanchita karmas, our stock of karmas.
 
As an illustration, consider this. The arrows in an archer’s quiver are sanchita karmas, the arrows that have left his bow are prarabdha karmas, and the arrows that are loaded on the bow are agaami karmas. The Vedas assert that so long as an individual maintains a stock of karmas, he has to take on a body to exhaust those karmas. In each birth, a portion of the stock of karmas is allocated to the individual so that he can exhaust them. By generating further selfish desires, the individual adds to his stock of karmas, and the cycle of birth goes on indefinitely.
 
Shri Krishna says that the one who has properly understood the relationship between Purusha and Prakriti, one who has understood the identification of the eternal essence with Prakriti due to ignorance and the consequent rushing after the gunaas, is never born again. This means that his stock of karmas is destroyed, just like a spark of fire destroys dry hay. He does not generate any further selfish desires, because he is no longer fascinated by the play of the three gunaas. Why does this happen? When one realizes that selfish desire is created by ignorance of one's true nature, it wipes out any notion of selfishness completely. There is no longer an urge to come into contact with Prakriti.
 
Now, this person still has to deal with his prarabdha. His present life karmas continue to be active until his body drops off, after which he does not have to take any further births. The word “api” in the shloka indicates that the individual can continue to perform his duties even if he has realized his true nature as the eternal essence, just like king Janaka continued to rule his kingdom even though he had achieved liberation.
 
Shri Krishna concludes the topic of Purusha and Prakriti with this shloka.

Bhagavad Gita Verse 27, Chapter 3

prakruteh kriyamaanaani gunaih karmaani sarvashah |
ahamkaaravimoodhaatmaa kartaahamiti manyate || 27 ||
 
All actions, in all situations, are performed by the gunaas of prakriti. He who is completely deluded by the ego thinks "I am the doer".
 
prakruteh : of prakriti
kriyamaanaani : act upon
gunaih : by the gunaas
karmaani : all actions
sarvashah : in all situations
ahamkaara : ego
vimoodhaatmaa : one who is complete deluded
kartaa : doer
aham : I
iti : in this way
manyate : thinks
 
We saw earlier that an ignorant person is attached to action while a wise person is not. But what exactly does it mean to be attached to action? Shri Krishna clarifies that point in this shloka, which is yet another deep shloka with layers and layers of meaning. We shall approach it step by step to grasp its essentials.
 
First, let us take the example of someone who has accomplished a great thing, for example, won a Grammy award for outstanding singing. If that singer truly examines her accomplishment, she will realize that there were so many people and situations that were responsible for her accomplishment.
 
To begin with, her parents probably encouraged her to pursue music seriously. Her music teacher taught her the theoretical aspects of music. She met other musicians who helped hone her craft. She came across a situation that inspired her to write her award-winning song. Her accomplishment was a product of all these factors.
 
Compare that singer to some other award-winning singer who thinks that it was he who did it all, and does not even acknowledge the contribution of others. The notion that "I am the doer" is called "ahamkaara" or the ego, and creates an "us-vs-them" attitude. Someone who is under the influence of the ego is called deluded in this shloka.
 
Let us now look at what is meant by gunaas and prakriti so that we can better understand the shloka. Just like our scientists have discovered that all of matter is made up of fundamental particles known as atoms, ancient rishis postulated that all matter or prakriti is made up of combinations of three essential forces: an inert force, an active force, and a harmonizing force. These three forces or gunas are known as tamoguna, rajoguna and sattvaguna respectively.
 
Now here comes a statement which is a little difficult to swallow. Like the singer whose accomplishments had very little to do with her "own" efforts, every action that we perform is in reality performed by prakriti that is comprised of the gunas.
 
So then who are "we"? We go back to the second chapter to remember that we are the eternal essence that is everlasting and all-pervading. Like the sun that enlivens the earth but does not itself do anything, the eternal essence does not perform any action. It only enlivens prakriti which is performing the action. Most of us that do not realize this truth, unfortunately, fall in the "ignorant" category. The next shloka shows us the goal : how to become wiser.
 
Footnotes
 
1. Prakriti is further subdivided into the following 24 components:
- 5 elements : space, air, fire, water, earth
- 5 mediums : sound, touch, form, taste, smell
- 5 sense organs : ear, skin, eye, tongue, nose
- 5 organs of actions : speech, grasp, movement, generation, excretion
- 4 internal organs : mind, intellect, memory, ego
 
2. Prakriti is also known as Maya