ahankaaram balam darpam kaamam krodham parigraham |
vimuchya nirmamaha shaanto brahmabhooyaaya kalpate || 53 ||

On who has given up egoism, force, arrogance, desire, anger, possessions, free from mineness, and serene, is fit for becoming the eternal essence.
ahankaaram : egoism
balam : force
darpam : arrogance
kaamam : desire
krodham : anger
parigraham : possessions
vimuchya : given up
nirmamaha : free from mineness
shaantaha : serene
brahmabhooyaaya : becoming the eternal essence
kalpate : is fit
When the monk has decided to focus on contemplation upon the self, he should take care to not harbour tendencies or traits that are remnants of life in the material world. Shri Krishna enumerates those traits in this shloka, beginning with ahankaara or egoism. Egoism refers to the notion of I-ness in anything that is in the realm of Prakriti. For most people, their body is their self. For some others, it is the intellect. Even if these are temporary, they will become obstacles in meditation. A similar obstacle is the sense of mine-ness or mamataa.
Kaama refers to desire and passion, and balam or force refers to power of desire and passion. If these is are not checked, then the mind will always rush towards some object or the other, and do so with an intensity that is hard to control. Darpam is arrogance, which makes one feel that he is above others, and therefore, can do whatever he wants. This will prevent the monk from following a strict regimen of meditation. Another obstacle in meditation is parigrah, the sense of possessing or hoarding things, which can distract the monk from pursuing his path.
Ultimately, when the monk has done his best to remove all notions of I and mine from his mind, ensured that his surroundings are calm and free of distractions, ensured that likes and dislikes are conquered, convinced himself that the world is nothing but a collection of names and forms, he gets the wonderful reward in the form of serenity or shaantihi. He recognizes his true self as the shuddha saakshi, the pure witness, free from identification from the mind or body. He is now ready for resting in, which is the same as becoming, the eternal essence, brahman.