The Gateless Gate, by Ekai, called Mu-mon, tr. Nyogen Senzaki and Paul Reps [1934], at sacred-texts.com
Wakuan complained when he saw a picture of bearded Bodhidharma: "Why hasn't that fellow a beard?"
Mumon's comment: If you want to study Zen, you must study it with your heart. When you attain realization, it must be true realization. You yourself must have the face of the great Bodhidharma to see him. Just one such glimpse will be enough. But if you say you met him, you never saw him at all.