kodo sawaki roshi
Concentration is not
to try hard to watch something.
In zazen, if you try to look at one spot,
you will be tired in about five minutes. This is
not concentration. Concentration means freedom.
So, your effort should be directed at nothing. You should
be concentrated on nothing. In zazen practice we say that
your mind should be concentrated on your breathing,
but the way to keep your mind concentrated
on your breathing is to forget all about
yourself and just to sit and feel
your breathing.
…If you
continue this practice,
eventually you will experience the
true existence which comes
from emptiness.
Shunryu Suzuki