I am not the sort of person who asks for explanations, so I never asked why we bow in such a fashion. I have heard that it is a Shinto practice whereby the clapping is symbolic of awakening the god, but I don't know that this is the truth. What I do know is what I have come to experience after years of performing this tiny little act day in and day out: connected.When people arrive for class, they have not yet shed their individual needs and fears. They bring their anxieties and the business of their lives into the dojo and onto the mat. They are not joined into one group with a shared purpose.
Becoming a community of mutual purpose is what the opening bow is all about. We line up together, and we demonstrate our willingness to humble ourselves. Doing it twice makes sure that it wasn't a mistake. That it wasn't done casually, or without thought for the meaning of the act.
When we clap, we are acting in concert, with immediate feedback as to how united we are. There should be only a single sound each time as every pair of hands comes together simultaneously. At least, when I hear that, I feel a lightness inside myself and I can't help but smile at the feeling of connectedness that fills me at that moment.
It's a lovely reminder of how we should practice Katori throughout the session -- connected to each other, fully engaged and responsive to our partner, our instructors and our fellow students. We need to pay attention to the full reality that emerges before us, and we need to allow our responses to that reality to emerge naturally and completely, without hesitation or preconception.
And each time when we open practice I get another reminder of all that, in one quick sharp sound we all share.