The meaning of Hatha Yoga, by B.K.S. Iyengar

“The meaning of ‘Hatha Yoga’ is Sun (Ha) and Moon (Tha), Yoga in which Sun is the soul and Moon is consciousness. Consciousness can be compared to a lens. Its inner surface faces the soul itself, and its outer surface comes in contact with the world. Inevitably a degree of grime attaches itself to that outer surface and obscures our vision. In fact it prevents us from seeing clearly what is outside, and it equally prevents the light of our soul from shining out. If our house is gloomy because the windows are dirty, we don’t say there is problem with the Sun; we clean the windows. Yoga cleans the lens of consciousness in order to admit the Sun.”

~ probably from the book, Light on Life, by B.K.S. Iyengar