If you go walking one day
and meet a person you think
may be the Buddha, ask him
what is the heart of all of the sutras.
If he answers you with Dharma
will you be certain this person
is not the Buddha?
If, on the other hand,
he says nothing at all,
and merely holds up a mirror,
will you be certain you
are seeing the Buddha?
Decide before he crosses
the river and is gone from sight.

A reflection on Case 1 of Bring Me the Rhinoceros (Koans)