Bodhidharma & the 2nd Zen Patriarch (Eka)
I have always found this pivotal conversation between Bodhidharma and Eka to be instructive.
After Eka repeatedly implores Bodhidharma to give him the "true teachings," the first zen patriarch roars back at Eka,
"The incomparable truth of the Buddhas can only realized by constant struggle, practicing what can not be practiced, bearing the unbearable. How can you, with your small virtue and your easy-going and conceited mind, dare to aspire to the true teachings?!"
This response contains the essence of the paradox embedded in zen (and other nondual teachings):
How can one practice "what can not be practice."
How is it possible to bear what is "unbearable"?
It reminds me of a Shaolin priest's answer to a student who asked him "How can I know what is possible?"
To know what is possible"
Listen for the color of the sky.
Look for the sound of the hummingbird's wings.
Search for the perfume of ice on a hot day.
If you have found these things,
You will know what is possible.