A short, finished list rather than an endless feed: 100 of the best yoga quotes ever written, picked out of the full yoga archive on QuoteForever. You will find B.K.S. Iyengar, Frederick Lenz, Dharma Mittra and Gary Kraftsow among them.
Read the list top to bottom, or use it as a starting point - every author name links to everything else they said, and every quote has its own page you can share or turn into an image.