For many Korean Zen practitioners, Chinese Zen master So Sahn’s collection of wisdoms, The Mirror of Zen, is second in standing only to the Buddha’s principles. So Sahn writes in The Zen of Confidence,

People who are attached to sutras and a scriptural teaching of words can lack faith in the living, mysterious experience of meditation that leads to a sudden insight. They are … attached to the stubborn habit of distinguishing between “true” and “not true.” Believing only what is written in holy texts, they are conceptually mesmerized by the treasures of others, instead of digging inside to discover the priceless gems of their own, lying deep within.