The challenge of yoga is to go beyond our limits - within reason. We continually expand the frame of the mind by using the canvas of the body. It is as if you were to stretch a canvas more and create a larger surface for a painting. But we must respect the present form of our body. If you pull too much at once, we will rip the canvas. If the practice of today damages the practice of tomorrow, it is not correct practice.
B.K.S. IyengarWhen you inhale, you are taking the strength from God. When you exhale, it represents the service you are giving to the world.
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