The Ganges Mahāmudrā is an advanced practice in Esoteric Buddhism. It is practice without practicing; to practice is itself no practice. Where the path of language is cut off and the sphere of mental activity ceases, one investigates the point at which not a single thought arises yet there is clear, lucid awareness, and at which, though there is clear, lucid awareness, not a single thought arises. Then one realizes that afflictions are bodhi, deluded thoughts are wondrous functioning, emptiness and existence are nondual, essence and function are one suchness, and all phenomena are Buddhadharma.

At the advanced age of ninety-four, Master Yuanyin (the elder Mr. Li Zhongding) spared no effort in lecturing on the sūtras, expounding the Dharma, and writing books. Following Essentials of Buddhist Practice and Realization, this book is another monumental work. It repeatedly offers earnest instruction, sets everything forth without reserve, and is vivid, lively, and illuminating by analogy. It is indeed a precious raft for liberating sentient beings and an essential key to attaining Buddhahood. It is hoped that all people of aspiration and goodwill who read this book will open the eye of wisdom, enter the gate of formlessness, develop great capacity and wondrous functioning, and cultivate inexhaustible vows of compassion, so as not to disappoint the elder's painstaking efforts.

January 1999. Respectfully prefaced by the junior student Xu Hengzhi.