You must do the asana with your soul. How can you do an asana with your soul? We can only do it with the organ of the body that is closest to the soul - the heart. So a virtuous asana is done from the heart and not from the head. Then you are not just doing it, but you are in it. Many people try to think their way into an asana, but you must instead feel your way into it through love and devotion
B.K.S. IyengarThe practice of yogasana for the sake of health, to keep fit, or to maintain flexibility is the external practice of yoga. While this is a legitimate place to begin, it is not the end. Even in simple asanas, one is experiencing the three levels of quest: the external quest, which brings firmness of the body; the internal quest, which brings steadiness of intelligence; and the innermost quest, which brings benevolence of spirit.
B.K.S. IyengarYoga has a threefold impact on health. It keeps healthy people healthy, it inhibits the development of diseases, and it aids recovery from ill health.
B.K.S. IyengarYoga has to be done with the intellect of the head as well as the intellect of the heart
B.K.S. IyengarHe who has learnt to control his tongue has attained self-control in a great measure. When such a person speaks he will be heard with respect and attention. His words will be remembered, for they will be good and true. When one who is established in truth prays with a pure heart, then things he really needs come to him when they are really needed: he does not have to run after them. The man firmly established in truth gets the fruit of his actions without apparently doing anything. God, the source of all truth, supplies his needs and looks after his welfare.
B.K.S. Iyengar