5.23, Sloka 23, Chapter 5:

Here it is said again that a person need not wait for the next life or any other life to free himself from the samsara. It can be done in this very birth itself. A person who is freed from the desires and anger caused by frustration of non-fulfillment of desires, will neutralize himself from the physical, emotional and emotional stresses of the life. This will ultimately cause happiness in the mind of the person.

The words free from desire and anger is again repeated in this sloka. Desire is the root cause for all stress in life. If we leave desires then stress will not be there.

5.24, Sloka 24, Chapter 5:

A person who withstands the urges of desire and anger will be happy. Noe lord Krishna says how a person can be happy from within. It is said that a person is happy if the person evokes the knowledge of “self” within himself. A person who is withdrawn from pleasures of external world will be happy if he starts looking within himself. When a person is immersed in the self and who sees self in all external objects, and practicing yoga ( trying to unite self-consciousness with universal consciousness) ultimately attains the knowledge which will lead him to the real truth.