The True Meaning of "Grinding a Brick Cannot Make a Mirror; Sitting in Meditation Cannot Make a Buddha"

In the old days, when the Patriarch Mazu Daoyi did not yet understand the cultivation and realization of the Buddha-dharma, he believed that becoming a Buddha could only be accomplished through sitting meditation, not knowing that becoming a Buddha is the result of combining meditative concentration (samādhi) and wisdom; only when samādhi and wisdom are perfectly integrated can one forge and transform the body-mind world. When Chan Master Huairang was searching for outstanding talents for Buddhism and encountered Mazu Daoyi, he saw that Mazu sat in meditative absorption all day long. Observing his extraordinary countenance and dignified bearing, possessing the heroic spirit of a patriarch, he wished to guide him into becoming a dragon and elephant of the Buddhist gate. Chan Master Huairang sat opposite Mazu Daoyi and took a brick, grinding it vigorously, which drew Mazu's attention. Chan Master Huairang explained that he was grinding the brick into a mirror. Mazu shook his head and said that grinding a brick cannot make a mirror. Chan Master Huairang replied that sitting in meditation likewise cannot make one a Buddha.

Thereupon Mazu Daoyi humbly asked how one could become a Buddha, and Huairang then explained to Mazu Daoyi the theory and path to Buddhahood. To become a Buddha, one must first understand the fundamental Buddha-nature; only after seeing the mind and seeing the nature can one become a Buddha. How does one see the mind and see the nature? Through Chan investigation. Of course, within Chan investigation there must be not only samādhi but also wisdom; with the equal cultivation of Samādhi and Prajñā, neither leaning to one side nor the other, can one open great wisdom, see the mind and see the nature, and thereby become a Buddha. On the path of cultivation, one must be perfectly complete in all dharmas without deviation in order to become a Buddha. Lacking wisdom and only cultivating samādhi single-mindedly, wisdom cannot be opened. Yet without meditative concentration, engaging only in reasoning, sentiment, and intellectual understanding, one likewise cannot open great wisdom. Only by combining the two can one be complete in all wisdom and perfectly become a Buddha. After Mazu Daoyi understood the principle of becoming a Buddha, he practiced diligently day and night, finally saw the mind and saw the nature, and became a patriarch of his generation.