Nanyue's "Polishing a Tile"
Mazu Daoyi spent his days sitting in meditation.
His teacher, Nanyue Huairang, took a tile and began grinding it against a stone in front of the hermitage.
Mazu asked,
"
What are you doing?" Nanyue replied,
"Polishing this tile to make a mirror." Mazu said,
"How can polishing a tile make a mirror?" Nanyue answered, "How can sitting in meditation make a Buddha?"
Reflection
Nanyue grinding a tile to make a mirror is a classic critique of mechanical meditation practice. Mazu's diligent sitting is met with an absurd analogy: polishing a tile cannot produce a mirror, just as sitting rigidly cannot produce a Buddha. The koan cautions against mistaking the form of practice for its essence. True awakening is not manufactured by effort; it is uncovered when the illusion of a self trying to become Buddha is seen through.