Monks ought to behave like a grinding stone.
Chang-san comes to sharpen his knife. Li-tsu comes
to grind his ax. Everybody who wants to have their
metals improved in any way makes use of the stone.
Each time the stone is rubbed it wears out, but it
makes no complaint, nor does it boast of its usefulness.
Those who come, go home benefited; some of them
may not be quite appreciative of the stone,
but the stone remains ever content.
(Selected by Sojun from a traditional Zen text)