prayatna persevering effort, continued exertion, endeavour
saithilya laxity, relaxation
ananta endless, boundless, eternal, infinite
samapattibhyam assuming original form, completion, conclusion
Perfection in an asana is achieved when the effort to perform it becomes effortless and the infinite being within is reached.
Perfection in asana is reached only when effort ceases, inculcating infinite poise and allowing the finite vehicle, the body, to merge in the seer.
The sadhaka can be considered firm in his postures when diligent effort is no longer needed. In this stability, he grasps the physiology of each asana and imbues within, reaching the minutest parts of the body. Then he gains the art of relaxation, maintaining the firmness and extension of the body and consciousness. In this way he acquires a sensitive mind. With this sensitivity, he grooms his thinking faculty to read, study and penetrate the infinite. He is engulfed in the boundless state of oneness, which is indivisible and universal.
Some say that it is possible to acquire mastery of asana merely by surrendering to God. This can never be so. In yoga one is always on a razor's edge and in asana perfection must be attained through perseverance, alertness and insight. Without these one remains dull and makes no progress. Surrendering to God alone does not make one perfect, although it helps one to forget the tensions of life and of the efforts put in, and guides one towards humbleness even when perfection in asana has been attained.
When the sadhaka has reached that state of balance, attention, extension, dissemination and relaxation take place simultaneously in body and intelligence, and they unite in the seat of the soul. This is a sign of release from the dualities of pleasure and pain, contraction and extension, heat and cold, honour and dishonour, etc.
Perfection in asana brings unalloyed happiness, blessedness and beatitude.