The dharanasu ca yogyata manasah sutra highlights a different aspect of pranayama. It not only leads one to enlightenment or complete stability of mind, it also acts as an agent of true knowledge that leads one towards the realisation of the soul.
dharanasu for concentration
ca and
yogyata fitness, suitability, propriety, ability, capability, appropriateness
manasah of the mind
The mind also becomes fit for concentration.
Pranayama is not only an instrument to balance the mind, but also the gateway to concentration - dharana.
Once the new light of knowledge has dawned through the practice of pranayama, the mind is fit and knowledgeable to move on towards the realisation of the soul. The allusion here is clear that the sadhaka who had to struggle initially to cultivate a yogic way of life by self-discipline and study, now finds his efforts transformed into a natural fervour to progress in his sadhana.
