From Chapter 8 ("Breathing In, Breathing Out") of Subtle Sound: The Zen Teachings of Maurine Stuart:

Someone came to me and said in disbelief, "This is spiritual practice, sitting on a cushion and counting from one to ten?"

Everything is spiritual practice. When you leave the zendo, you go back to all kinds of life situations; you are not taking anything with you. You are going back with nothing. Not a thing. You are going back, however, to respond to whatever your life situation is, vividly. This is what our practice is about. Some people are doing koan study. It's not what you say to me in your response, it's how you respond. And how do you respond to your life? Don't take anything with you. Then there's just this cleared-up mind that responds to whatever is asked of you.

Those of you who are doing this strange spiritual practice of counting your breaths are discovering that it's exceedingly wonderful; it is incomparably the best way to take us into the ocean of samadhi (one-pointed concentration). Just counting: it's difficult to do, to count from one to ten, again and again. To reach a unified, single-minded state, this method has been used for generation after generation after generation. When you begin counting, there are many thoughts. Thoughts come in and thoughts go out, and eventually, the counting takes over and you are deeply engaged in vast—what? And then, just naturally, counting stops. And you're just watching the breath, breathing the in-breath, breathing the out-breath. And then even that falls off, and you're just purely being. The thought of practicing Zen is gone. The thought of successful practice is gone. Scattered mind is gone. There's just simply one-mindedness, and then no-mindedness: Mu-shin. Nothing seeking, or striving, or getting; just counting. Just breathing. Just being. Just this.

_{(cf. Being with Your Breath (2010-02-20), Waking Up to What You Do (2010-03-21), Coming Back to Your Breath (2011-09-25), This (2013-03-09), No Beginning, No End (2013-03-24), Mantra - Mindfulness, Nonattachment, Oneness (2017-01-25), ...) - ^z - 2017-04-03}