Let go of your worries  
and be completely clear-hearted,  
like the face of a mirror  
that contains no images.  
If you want a clear mirror,  
behold yourself  
and see the shameless truth,  
which the mirror reflects.  
If metal can be polished  
to a mirror-like finish,  
what polishing might the mirror  
of the heart require?  
Between the mirror and the heart  
is this single difference:  
the heart conceals secrets,  
while the mirror does not.
Mewlana Jalaluddin Rumi
http://www.poemhunter.com/poem/let-go-of-your-worries/