Shantideva
Where would I possibly find enough leatherWith which to cover the surface of the earth?
But wearing leather just on the soles of my shoes
Is equivalent to covering the earth with it.
Likewise it is not possible for me
To restrain the external course of things;
But should I restrain this mind of mine
What would be the need to restrain all else?
-- Shantideva ( full text commentary )