"Two hands clap and there is a sound.
What is the sound of one hand?.."
- Hakuin Ekaku
I love this koan. Sort of like how we humans are so keen to grasp concrete concepts but not so much when it comes to things which are more subtle and not so easily expressed into words. It's kind of funny too when you actually go to clap your hands and then real fast throw just one hand up there. I don't know why but it just cracks me up every time!