1900 In the early morning of June 22nd, 2000, the Taoist King of Mogao Grottoes accidentally opened the secret darkroom hidden behind the north wall of Cave 16 for more than 900 years. This is the later world-famous Dunhuang Tibetan scripture cave. Taoist Wang had expected to start with a lot of gold and jade jewelry, but he only saw piles of ancient manuscripts, prints, banners, silk paintings, bronze buddhas and worn-out utensils, about 50 thousand pieces. Road flyover Wang, who is proficient in writing, is inevitably disappointed. What he doesn't know is that this collection is an academic treasure, which soon gave birth to a new international school-Dunhuang studies! After the news of the discovery of the Tibetan Sutra Cave in the Mogao Grottoes came out, various legends circulated among the people in Dunhuang. Some say that the Buddha in the Mogao Grottoes has appeared, which also shows a paradise; Some people say that Taoist Wang made a windfall ... Taoist Wang was so happy and afraid that he couldn't sit still. So I made up a sensational myth: "During the reign of Guangxu (Gregorian calendar:1June 22, 900), in the early morning of the twentieth day in wuyue, there was a sudden gunshot, and the mountain suddenly split and cracked. The original workers used hoes to dig. Fortunately, there was a flash Buddha cave with a stone tablet ... in the thirty-second year of Guangxu (1906), which stood in Tibet. Xia Meng Gengzi (1900) opened a new cave with a wall to the north, and the cave was dug again. There were Buddhist scriptures in it, which filled the space, and the bronze Buddha was full ... "... Wang Daoshi's tombstone also said that Wang Daoshi" dredged three layers of cave sand with running water, and the sand came out, and the wall cracked a hole, as if there was light. "The wall is broken, there will be a small hole, be suddenly enlightened. There are thousands of volumes of Tang poetry classics and many antiques in it. " What the two monuments say is obviously more credible than Wang Daoshi's "Tianpao Mountain Crack Theory". People have ruled out rumors such as "the Buddha shows his spirit" and "Wang Daoren gets rich with treasures", and have painstakingly thought about why these collections of Buddhism, Taoism, Confucianism, classics, history, law, rules, silk paintings, bronze buddhas and buddhas are gathered together. Why is it sealed? What time does it close? This is the "mystery of the Dunhuang Tibetan scriptures cave" that people have not yet solved. There are two kinds of guesses about why the collection gathered: one is that this part of the collection came from the Mogao Grottoes and was temporarily gathered after years of collection and long-term accumulation; The second guess is that only the tattered Buddhist scriptures, Buddhist paintings, broken documents, outdated documents and graffiti written by scholars eliminated by Buddhist temples are gathered for unified storage out of "respecting the saints" and "cherishing calligraphy paper". There are roughly two kinds of corresponding speculations about the reasons for the storage: First, the collections in the Tibetan scriptures cave are broken, outdated and scrapped, and under the control of the concept of "respecting the saints and respecting the scriptures", these tattered documents and Buddhist paintings are still inviolable "sacred waste". Therefore, it is necessary to collect and seal it centrally. This theory is represented by Stein, Fujitsu and Fang Guang. On the other hand, it may be that the monks in Mogao Grottoes fled the war. This part of the scriptures and bronze instruments is inconvenient to carry and can't bear to lose. So they were sealed in the secret room and painted bodhisattva on the sealed wall to hide their eyes and ears. Most scholars advocate this point. There are different opinions about the closing time of this cave. General: 1. After 995 AD (from the Northern Song Dynasty to the first year of Daoism), represented by pelliot Stein; 2. Later it was AD 1002, represented by Fujitsu and He Changlin; 3. The period between1002-1014, represented by He Shizhe; 4. During the period of1002-1030, Bai Bin was the representative; 5. After A.D. 1006, Rong Xinjiang was the representative; 6. 1030— 1035, represented by Bi Sujuan; 7. Before Xixia conquered sandbars in A.D. 1035, it was represented by Luo Zhenyu, Jiang Liangfu and Yan Wenru; 8. After A.D. 1049- 1054 (Year of the Emperor), represented by Chen Yuan, Shi and Ma Shichang; 9. A.D. 1094- 1098 (The Age of Little Saints), represented by Yin Qing and Tan Zhen; 10. A.D. 1228 years ago (before the Mongolian army attacked Dunhuang), represented by Guan Baiyi; 1 1. A.D. 1348- 1368 (Yuan and Ming Dynasties), represented by Zhang Weiwei and others. Most of the above statements are based on the premise of avoiding war, or the threat of Yunxixia, or the threat of Yunhala khanate, or the threat of YunMongolia, or the war in the last years of Yunyuan; Only Hiroichi Fujiki and Fang Guang believe that the closure of the Tibetan Sutra Cave is a normal waste and has nothing to do with the threat of war. But academic issues cannot be judged by "votes". This makes the mystery of the Tibetan Sutra Cave even more confusing. The key to solve the mystery of Dunhuang Tibetan Sutra Cave is to find out the closing time of the Tibetan Sutra Cave. After this question is clarified, other related questions, such as what kind of caves belong to? Why are you gathering? Why is the Tibetan Sutra Cave closed? Wait, it's possible to solve it. In order to find out the closing time of the Sutra Cave, there are two major questions: (1) What are the latest collections of the Sutra Cave and when? (2) When was the portrait of the sacrificial bodhisattva painted on the north wall of the tunnel in Cave 16 (hidden body at the entrance of the Tibetan Scripture)? The former question is related to the upper limit of the closed time of the Tibetan sutra cave; The latter question is related to the lower limit of the closing time of the Tibetan Sutra Cave. In the past, scholars' discussions only focused on marginal issues and failed to concentrate on tackling key problems. So although some peripheral obstacles were removed, the king was still not captured alive. Therefore, the mystery of the Tibetan Sutra Cave remains unsolved. It seems that a small mystery of the Tibetan Sutra Cave is also a systematic project of Dunhuang studies-fashion is difficult to clear. Therefore, the mystery of the Sutra Cave will inevitably last for some time.