The background story of this Koan
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."
The original Chinese Goang
because a monk asked, “'Honored Ones (Skt. Bhagavān) of the ten directions, one path to the gate of Nirvana.' I do not yet really know the trailhead. Where's its location?”
Feng picked up and raised his staff, drew one dividing line and said, “Within this.”
Later [a/the] monk asked Yunmen to augment this.
Men picked up and raised his fan and said, “This fan streaks like a comet leaping up to the thirty-third heaven shoving into the nostril of the god Sakra.
The carp of the Eastern Sea gets one hit with a stick and the rain seems like an overturned basin.”
Traditional Commentaries and .... Poems (Gata)
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.
One person’s direction goes to the deep sea bottom and on the sea floor scatters dust.
One person on the highest mountain peak sets up white waves that overflow the sky.
Holding firm or letting go, each puts forth one single hand to support and keep upright the lineage.
Riding on, they greatly seem like two individual racers colliding into each other at the finish of the race.
In the world and above you meet people without straight foundations.
Coming at it with the insight (Skt. vipassana) of the true eye, neither of the two great elders knows where the trailhead is at.