Bhagavad Gita Verse 41, Chapter 4

yogasannyastakarmaanam jnyaanasanchinnasanshayam |
aatmavantam na karmaani nibhandanti dhananjaya || 41 ||
 
One who has renounced actions through yoga, one who has severed all doubts through knowledge, such a self-poised person is not bound by actions, O conqueror of wealth.
 
yoga : yoga
sannyasta: one who has renounced
karmaanam : actions
jnyaana : knowledge
sanchinna : severed
sanshayam : all doubts
aatmavantam : self-poised
na : do not
karmaani : actions
nibhandanti : bind
dhananjaya : O conqueror of wealth
 
Shri Krishna now begins to conclude the fourth chapter with this shloka. He re-emphasizes that one who follows the path of karma-sanyaasa, or renunciation of action, is liberated from all bondage. He refers to Arjuna as Dhananjaya, which means conqueror of wealth, because Arjuna had accumulated massive wealth from conquests of kingdoms. Also, he had gained wealth in the form of knowledge from Shri Krishna.
 
One who has attained the knowledge of self-realization acts without a sense of doership and enjoyership of action. It is important to note that renunciation of action refers to renunciation of doership and enjoyership, not renunciation of the action itself. Actions continue to happen. Furthermore, this yoga or prescribed methodology needs to be learned from a teacher, it is difficult to learn on one's own.
 
Shri Krishna also reiterates the knowledge of self realization dispels all doubts in the seeker's mind. Till this knowledge is attained, doubts such as who is the doer of action, who is the enjoyer of results, what is the relation of the self to action will remain. One who has gained this knowledge and dispelled all such doubts is called "aatmavant" or one who has gained knowledge of our own self.
 
A classic example here is that the space in a pot thinks that it is the pot. Once it knows that it is space, it immediately realizes that it is not subject to modifications like big or small, brown or white, moving or stationary and so on. From that point on, any change to the pot will not affect the space in the pot. Similarly, once our doubts vanish, our actions will not bind us.