Shitou Xiqian (700-790) (石头希迁; pinyin: Shítóu Xīqiān; Wade–Giles: Shih-t'ou Hsi-ch'ien, Japanese: Sekitō Kisen) was an 8th-century Chinese Chan Buddhist teacher and author. From the ninth century onward, all of the Zen masters of subsequent generations - such as Baizhang, Huangbo, Linji, Nanquan, Zhaozhou, etc. - claimed lineage from Shitou and his contemporary Mazu. Together, they were known as the 'Two Doors of Immortality'.
After Huineng died at Caoxi in 713, tradition holds that he left behind more than forty Dharma successors. Many of them seem to have withdrawn into the mountains, forsaking life and teaching careers in the established Chan monasteries, which would not have been numerous in those early times. In truth, we have no way of knowing how many successors the historical Huineng had, given that the information in his epitaphs and in the available documents from the period bear little resemblance to the account given in the Platform Sutra.
Traditionally, two of Huineng's disciples handed down mind-to-mind Dharma transmission from the Sixth Patriarch to the two leading ancestors of all the surviving Chan schools in China: the first, Nanyue Huairang (677-744) became the teacher of Mazu, while Qingyuan Qingsi (660-740), who taught at Qingyuan Mountain (monastery) in Jiangxi, appointed Shitou Xiqian his Dharma successor in 740.
Not much is written about Qingsi in the Sung-period chan histories, although Jingde chuan deng lu does state specifically that he was the foremost student of Huineng. This has led some historians to speculate that Qingsi was invented by the Song historians to document an authentic lineage between Shitou's successors and Huineng. But it could be equally true that simply not much was known of him. In any event, the biography and record of Qingsi present some important information about Shitou Xiqian. Especially interesting is the circumstance that Shitou, who would have left Huineng as a boy at the age of 13, is shown in this text to be already clearly awakened, so that Qingyuan's purpose is just to test his understanding and to give him Dharma succession.
As the Sixth Patriarch lay dying, Xiqian asked, "Who will I go to after you die?" The Sixth Patriarch said, "You'll have to answer that question by yourself." After his death, Shitou sat quietly in meditation, as if it were he who had died. The head monk said to him, "The Master's gone, why keep sitting?" Shitou said, "It's what he told me to do." The head monk said, "Your teacher is now Qingsi, who lives at Qingyuan. He'll instruct you from now on – you'll only get confused if you stay by yourself." Shitou accepted the advice, bowed to the remains of the Sixth Patriarch, and left for Qingyuan Monastery.
Qingsi asked Shitou where he had come from. Shitou said from Caoxi. Qingsi asked, "What have you brought with you?" Shitou replied, "I had everything I needed before I went to Caoxi." Qingsi said, "If that's so, why did you go there?" Shitou answered, "If I hadn't gone there, how would I have known it?"
Shitou asked Qingsi, "Did you know the master of Caoxi?" Qingsi said, "Do you know me?" Shitou said, "If I knew you, would I understand you?" Qingsi said, "I have many cows with horns, but just one unicorn." [Qingsi says that he has many students, but Shitou is unique among them.]
It is recorded that Huairang was a teacher and abbot of a temple about a half-mile away from Shitou's temple, at the time Shitou arrived on South Mountain.
When Shitou had arrived at Nantai Temple, a monk saw him and went to tell Monk Rang. "The young man who came to ask you some questions recently and who was very impolite is now sitting and meditating on a rock over to the east of here." "Really?" "Yes, indeed." Then Rang told his attendant, "Go over to the east side of the mountain and tell him that a person of such firm intention would also be welcome over on this side." The attendant delivered the message. Shitou answered, "I don't care how often you ask me, I am not coming over to your side of the mountain!" The attendant returned with the answer. Rang said, "Nobody will ever get the better of this man."
Though there is no evidence that the two masters ever met, it is obvious that they held each other in high esteem. Many of the important Ch'an monks studied with both masters. Very often one of the masters will advise a particular disciple to go to the other master and study with him. As the saying from that period goes, "Ta-chi was the master in Kiangsi; Shitou was the master in Hunan. Those who were wavering and didn't go to see these two great teachers were considered completely ignorant." As they represented the start of a new era in Chan (through which Mazu and Shitou were the 'bottleneck'), from the beginning of the ninth century on, all Ch'an masters were considered spiritual descendants of Mazu and Shitou.
After the completion of Huineng's teaching and the dismantling of his school, Zen quietly and informally penetrated the ancient Buddhist establishments, then burst into bloom under the guidance of two extraordinary Zen masters of the eighth century, Shitou and Mazu. These two teachers were known as "the two doors of immortality," and almost all of the known Zen masters of the following generation were taught by both of them. (Cleary)
With Shitou and Mazu, Ch'an entered a new phase of development. The meditation instructions of Daoxin and Hongren, and Huineng's simultaneous cultivation of samadhi and prajna gave way to a new teaching style that was refreshingly open and direct. Many of the teaching devices that later on came to be identified with the Ch'an school-such as shouts, blows, enigmatic questions were first used by Mazu. This change in teaching style initiated by Mazu and his followers, coupled with the change in the literary format used to record their teachings, have even led some to perceive discontinuity between the Ch'an of Huineng and Mazu.
I would rather sink to the bottom of the sea for endless eons than seek liberation through all the saints of the universe. Shitou (石頭) (The Golden Age of Zen 270, 323 n.57)