” An asana must be righteous and virtuous. By righteous I mean that it must be true. You must not cheat or pretend. You must fill every inch of your body with the asana from your chest and arms and legs to the tips of your fingers and toes so that the asana radiates from the core of your body and fills the entire diameter and circumference of your limbs. You must feel your intelligence, your awareness, and your consciousness in every inch of your body.
By virtuous I mean that is must be done with the right intention, not for ego or to impress but for the Self and to move closer to (Source).
In this way the asana is a sacred offering.We are surrendering our egos. This is supreme devotion to (the Universe). It must not be just your mind or even your body that is doing the asana. You must be in it. 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 must instead feel your way into it through love and devotion.” ~BKS Iyengar