” […] right thinking leaves no shadow. Thinking which leaves traces comes out of your relative confused mind. Relative mind is the mind which sets itself in relation to other things, thus limiting itself. It is this small mind which creates gaining ideas and leaves traces of itself.

[…]

In order not to leave any traces, when you do something, you should do it with your whole body and mind; you should be concentrated on what you do. You should do it completely, like a good bonfire. You should not be a smoky fire. You should burn yourself completely.  If you do not burn yourself completely, a trace of yourself will be left in what you do. You will have something remaining which is not completely burned out. Zen activity is activity which is completely burned out., with nothing remaining but ashes. This is the goal of our practice.”