The 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. IyengarIn backbends, one touches the body physically, mentally, intellectually, consciously and spiritually everywhere.
B.K.S. IyengarThe primary aim of yoga is to restore the mind to simplicity, peace, and poise, to free it from confusion and distress.
B.K.S. IyengarMind is the king of the senses; breath is the king of the mind; and the nerves are king of the breath.
B.K.S. IyengarAs a breeze ruffles the surface of a lake and distorts the images reflected therein, so also the chitta vrtti (fluctuations of mind) disturb the peace of the mind. The still waters of a lake reflect the beauty around it. When the mind is still, the beauty of the Self is seen reflected in it.
B.K.S. IyengarWhenever asana is done mechanically from the front brain, the action is felt only on the peripheral body, and there is no inner sensation, there is no luminous inner light. If the asana is done with continual reference to the back of the brain, there is a reaction to each action, and there is sensitivity. Then life is not only dynamic, but it is also electrified with life force.
B.K.S. Iyengar