The Gateless Gate, by Ekai, called Mu-mon, tr. Nyogen Senzaki and Paul Reps [1934], at sacred-texts.com
A Zen pupil asked Kembo: "All Buddhas of the ten parts of the universe enter the one road of Nirvana. Where does that road begin?"
Kembo, raising his walking stick and drawing the figure one in the air, said: "Here it is."
This pupil went to Ummon and asked the same question. Ummon, who happened to have a fan in his hand, said: "This fan will reach to the thirty-third heaven and hit the nose of the presiding deity there. It is like the Dragon Carp of the Eastern Sea tipping over the rain-cloud with his tail."
Mumon's comment: One teacher enters the deep sea and scratches the earth and raises dust. The other goes to the mountain top and raises waves that almost touch heaven. One holds, the other gives out. Each supports the profound teaching with a single hand. Kembo and Ummon are like two riders neither of whom can surpass the other. It is very difficult to find the perfect man. Frankly, neither of them know where the road starts.