The Gateless Gate, by Ekai, called Mu-mon, tr. Nyogen Senzaki and Paul Reps [1934]
Hoen said: "The past and future Buddhas, both are his servants. Who is he?"
Mumon's comment: If you realize clearly who he is, it is as if you met your own father on a busy street. There is no need to ask anyone whether or not your recognition is true.