One day, a monk noticed that Zen Master Yao-shan was reading the sutra.
“Master, you normally don’t allow us to read sutra. Why are you reading sutra yourself?” The monk asked.
“Oh, I read only to cover my eyes.”
“So can I do that too?” The monk asked.
Master Yao-shan said to the monk: “For you, you must see through cowhides.”