It was said that there was an old Zen master in ancient times. One evening, while taking a walk in the Zen courtyard, he suddenly saw a chair in the corner of the wall. He knew at a glance that a monk had violated the temple rules and climbed over the wall to wander around. However, the old Zen master didn't make a fuss. He walked to the wall, moved the chair away, and squatted on the spot. A little while later, sure enough, a young monk climbed over the wall, and in the dark, stepped on the back of the old Zen master to jump into the yard. When his feet touched the ground, he realized that what he had just stepped on was not the chair, but his own master.