Pranayama teaches the aspirant to regulate his breathing and thereby control the mind.
B.K.S. IyengarAs long as you do not feel the serenity in the body, in each and every joint, there is no chance for emancipation. You are in bondage. So while you are sweating and aching, let your heart be light and let it fill your body with gladness. You are not only becoming free, but you are also being free. What is not to be glad about? The pain is temporary. The freedom is permanent.
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. IyengarYou have to get rid of borders, limits, and classifications; then light comes. We see everything on the screen of our ideas. We must get rid of that screen to be able to see what is behind. X's ideas are limited, that is why he remains on the surface. Y got rid of the limits, so she always goes to the depths. We should always meet people and new subjects with no set frame of mind. We have to live like that even after long acquaintance. We must get rid of every set idea to approach everything and everyone with love.
B.K.S. Iyengar