Zen practice … requires great faith, great courage, and great questioning.
What is great faith? Great faith means that at all times you keep the mind which decided to practice, no matter what. It is like a hen sitting on her eggs. She sits on them constantly, caring for them and giving them warmth, so that they will hatch. If she becomes careless or negligent, the eggs will not hatch and become chicks. So Zen mind means always and everywhere believing in myself…
Great courage … means bringing all your energy to one point. It is like a cat hunting a mouse. The mouse has retreated into its hole, but the cat waits outside the hole for hours on end without the slightest movement. It is totally concentrated on the mouse-hole. This is Zen mind — cutting off all thinking and directing all your energy to one point.”
Copied from Brain Prickings