Deshan Xuanjian (Chinese: 德山宣鑒; Wade–Giles: Te-shan Hsuan-chien; Pinyin: Déshān Xuānjiàn; Japanese: Tokusan Senkan), was a Chinese Zen Buddhist monk during the Tang Dynasty. He was born in Jiannan in what is now Sichuan Province. He is remembered for hitting his students with a cane to express awakening. Through his student Xuefeng Yicun, he is the ancestor to two of the Five Houses of Zen, the Yunmen School and the Fayan School. Earlier in his life he was a scholar focused on the Vinaya, and later he became famous for his knowledge of the Diamond Sutra. However, a famous kōan story recorded in the Blue Cliff Record and Shōbōgenzō Shin fukatoku relates an encounter he had with an old woman that convinced him that scriptural study on its own fails to bring about awakening. After this he studied under the Zen teacher Longtan Chongxin. During the reign of Emperor Wuzong of Tang, the brief but intense Great Anti-Buddhist Persecution was initiated and Deshan was forced from a thirty year long position in Lizhou into hiding on Mt. Dufu. Afterwards the governor of Wuleng in what is now Hunan Province asked Deshan to come to live on Mount Virtue, known in Chinese as "Deshan", the mountain after which he is named.

Master Deshan Xuanjian cane from the northern region of Jianzhou in the far western province of Sichuan. As a young monk he first made extensive studies of monastic discipline, and then turned his attention to studying the “Mind-Only” (Vijnanavada) School of Philosophy, as well as becoming an expert on the Diamond Sutra, a scripture usually associated with the “Middle Way” (Madhyamika) School. He became a respected scholar, and for many years made a career as a lecturing priest. Eventually becoming intrigued by the Zen movement, he traveled to Hunan to seek out a master.

　

　

One day during Xuanjian's travels he came across an old woman selling steamed dumplings on the side of the road. Stopping for a rest, he set down his heavy pack and asked the woman for some dumplings. The old woman pointed to the bundles of manuscripts tied to his pack and asked, “Venerable, what is that you're carrying?”

　

Xuanjian said, “They're commentaries on a scripture.”

　

The woman asked, “Which scripture are they about?”

　

Xuanjian said, “The Diamond Sutra.”

　

The woman said, “I have a question for you. If you can answer, I'll give you some dumplings fir free. But if you can't answer, you'll have to find something elsewhere. Okay?”

　

Xuanjian said, “Go ahead and ask.”

　

The woman said, “In the Diamond Sutra it says that the mind of the past can't be grasped, the mind of the future can't be grasped, and the mind of the present can't be grasped, either. So with what mind is the venerable asking for dumplings?”

　

Xuanjian was speechless.

　

The old woman then suggested that he seek out Master Longtan Chongxin at the nearby Dragon Pool Temple for guidance. (The old woman had probably been a student of Master Longtan's. The master, because of his humble background as a rice-cake seller, was, perhaps, particularly open to teaching people from all classes and backgrounds). Xuanjian took the advice and headed toward the Dragon Pool.

　

When he arrived at the temple, Xuanjian sought out Master Longtan, and on first meeting him said, “I've been hearing about the Dragon Pool, but now that I've arrived I see no pool, and no dragon has appeared.”

　

The master replied, “Ah, you've truly arrived at Dragon Pool.”

　

　

That evening Xuanjian was invited to the abbot's room. He talked extensively about Buddhist philosophy until Master Longtan finally said, “It's getting late. You should go now.” So Xuanjian said good night and stepped outside. But finding it too dark to make his way, he asked the master for a lamp. The master lit a lantern and brought it out, but just as Xuanjian reached out to take it, the master blew it out. At that moment Xuanjian had a deep awakening. He then made a deep bow to the master.

　

The master said, “What did you see that makes you bow?”

　

Xuanjian said, “From now on, I'll never doubt the teaching of the venerable master.”

　

The next morning Xuanjian piled all his scholarly texts in front of the Teaching Hall. Lifting a torch he said, “All these abstract doctrines are like a single hair in vast emptiness. All the affairs of the world are like a drop of water in a boundless ocean.” Then he burned them all.

　

　

While spending many years with Master Longtan, Xuanjian traveled around the region and met other teachers, receiving guidance particularly from Master Guishan Lingyou. Sometime after the Huichang era persecution came to an end, Xuanjian made an impression on some regional officials, and the Prefect of Wuling in southern Hunan invited him to become the abbot of a newly restored monastery on Virtue Mountain (Deshan). Here he remained as master for the rest of his life, supposedly attracting hundreds of students, and becoming famous for a direct, physical, and even fierce teaching style.

　

　

Once a monk asked Master Deshan Xuanjian, “What is awakening?”

　

Deshan struck him with his staff and said, “”Get out, don't defecate here!”

　

Then the monk asked, “What is Buddha?”

　

The master said, “An old beggar in India.”

　

　

One day Master Deshan said to the community, “As soon as you ask, you've missed it. If you refrain from asking, you've also missed it.”

　

Then a monk came forward and made a bow.

　

The master hit him.

　

The monk said, “I haven't even asked anything yet. Why did you hit me?”

　

The master said, “What difference would it make if I'd waited until you spoke?”

　

　

When Master Deshan became sick at the end of his life, a monk asked him, “Is there one who is not sick?”

　

The master said, “Yes.”

　

The monk asked, “What about the one who is not sick?”

　

The master moaned, “Uuugh. Uuugh.”