My friend Claudia gives a nice intro to the story of the text over on her blog
Without chanting and study of the scriptures (anadhyayana), the practice of yoga , without sense control or meditation (samyama), the body breath and the mind get restless. !
Regular practice of yogangas and study and chanting of the scriptures will help remove disturbances during meditation and worship of the Lord.
In the viniyoga chapter the practices for one’s benefits were explained. Now, some practices that will help one in the spiritual goal (atmarti)
￼If God does not exist, He does not, even so there is no loss for the believer in God. But for the non -believer, if God exists the loss is immense indeed. The nature of God is self revealing, beyond the scope of senses and mind.
Agitation of the mind, trembling of the body all happen in an intensified form always due to eating without any niyama or control.
If one wants to experience the Highest, one should practice Pranayama. It also prevents illness of intestines, spleen, liver and bladder.
The disturbances of breath lead to the diseases of the kosas. And by the practice of Pranayama alone, can the kosas be purified.
By adopting proper disciplined procedures of Yoga, which consistent with one’s capabilities, the breath comes under one’s control. There is no other method.