难经者。灵素之精华也。灵素犹多假托。难经则扁鹊手着之书。继往圣开来贤。允为医林之
准的。奈古籍久湮。世传多误。由是解者臆度。读者狐疑。难经晦而灵素不彰。灵素不彰而医道或
几乎息矣。余向至吴门。访求医学。遇歙友金子。赠古本难经。读之则纲举目张。脉通络贯。视世传
之错谬。不啻拨云雾而睹霄汉矣。乃遍考诸家。逐一校对。无如此卷之经明注晰者。宝之箧中
。携归谋付枣梨。以公同志。幸得好古之士。力赞斯役。不数月而书成。俾数千年隐晦之书。一
旦光昭宇内。是医道之幸。亦即凡有疾苦者之浓幸也。其功顾不伟欤。故略序其梗概。以志不
忘所自云。
嘉庆五年岁次庚申仲春近溪张基序
余少学医。从云间嗣宗何夫子游。近侨寓金阊。常与上洋王修沈子究论医典。农轩之训。犹之
六经。扁鹊仲景犹私淑尼父之孟氏。是以内难伤寒。实医门鼎足之三经也。自汉而下。名贤继
出者。惟本此而已。后代作者。非不各有发明。然日就褊浅。致今之学人。乐浅而畏深。趋末而忘
本。呜呼。经义不明。医术奚恃。安得有好古之士。尚论三经。引宋仁宗朝嘉 故事。上请圣天子
诏儒臣及精通其事者。参古酌今。编纂全书。颁行宇内。为万世苍生计乎。适有客告余曰。向之
所谓难其人者今得之矣。姓丁氏。号适庐。从茸城携古难经加以阐注。来吴就梓。余闻之。始则
异。既则疑。因忆先师曾述宋时丁德用难经补注言。华元化得越人书被执乃烬。今之流传者。
皆吴太医令吕广重编。文多错简。辞意难明。十七家之注。如滑氏等仅存疑义。莫从考证。或有
古本。惜未显于世耳。今子所闻。莫非吴氏之古本欤。客曰否。因偕沈子访之。见其人。飘然鹤发。
非世俗之流。读其书。非素见之书。方知难经本来辞明理贯。并无一字衍文。故东坡楞伽跋云。
如医之难经。句句皆理。字字皆法。必有见而云然。益征师言有自矣。噫。二千余年若晦若灭之
书。一旦复显。使天下人知八十一难。乃越人之注内经也。而先生之文。又疏越人之注义也。一
若中天之日。纤微毕照。将见此本一出。则十七家之本可尽废矣。先生已成不朽之功。岂常人
所能及哉。丁子避席曰。河图洛书。因圣人而出。世秘之书。俟圣朝而显。此亦理数之使然也。我
何人斯。而敢与其功焉。余因乐其遇而纪其事。敬述于简末。
乾隆三年戊午阳月洞庭菊坡居士严茂源书
《难经》是《灵枢》和《素问》（合称《黄帝内经》，中医经典著作）的精华所在。《灵枢》和《素问》多假托之作，而《难经》则是扁鹊亲笔所著。它继承前代圣人的智慧并开启后贤的智慧，确实是医学界的准则。无奈古籍久已湮没，世间流传的版本多有谬误。因此，解说者往往主观臆测，读者心中充满疑惑。《难经》晦涩不明，《灵枢》和《素问》也不够彰显，若《灵枢》和《素问》不彰，那么医道恐怕就要几乎断绝了。
我先前前往苏州（吴门），访求医学知识，遇到一位来自歙县的朋友金子，他赠送给我一部古本《难经》。阅读这部书，则纲领清晰、条目分明，脉理贯通、经络连贯，与世间流传的错误版本相比，简直如同拨开云雾见到天空一样明朗。于是，我广泛考证各家注解，逐一进行校对，没有哪一卷像这一卷那样经文明确、注释清晰的。我将它珍藏在箱箧中，带回打算刻印出版，以公之于志同道合的人。幸好得到喜爱古籍之士的大力赞助这项事业，不到几个月书就刻成了。这使得数千年来隐晦不明的书籍，一旦在天下光明显耀，这是医道的幸事，也是所有遭受疾病痛苦者的巨大幸运啊。这功劳难道不伟大吗？所以我简略地叙述其大概经过，以表示不忘书本的来源。
嘉庆五年岁次庚申仲春，近溪张基作序。
我年少时学习医学，跟随云间嗣宗何先生游学。近来侨居在金阊（苏州），常与上洋王修沈先生探讨医学典籍。农轩（指神农氏、轩辕黄帝，代指古代医学源头）的教诲，就像六经（儒家经典）一样重要；扁鹊和张仲景对于孔子而言，就如同孟氏（孟子）私淑孔子一样。因此，《难经》（内难）、《伤寒论》（外难）实际上是医学门户鼎足而立的三部经典。自汉代以来，名贤相继出现，都是依据这三部经典罢了。后代作者，并非没有各自的发明创造，然而日益变得狭隘浅薄，导致如今的学人，喜欢浅显而畏惧深奥，追求细枝末节而忘记根本。唉！如果经义不明确，医术依靠什么来支撑呢？怎么才能得到那些喜爱古籍的人士，共同研讨这三部经典，援引宋仁宗朝刊校医书的旧例，向上请求圣明的天子诏令儒臣及精通此事的人，参考古代、斟酌现代，编纂全书，颁行天下，为万代百姓谋福祉呢？
恰好有客人告诉我：以前所说的难以找到合适人选的事，现在找到了。这位姓丁，号适庐，从茸城（上海松江一带）带着古本《难经》加以阐发注释，来到苏州准备刻印。我听说后，起初感到诧异，接着产生怀疑，于是想起先师曾讲述宋代丁德用补注《难经》的故事：华元化得到越人（扁鹊）的书后被逮捕，书被烧毁，如今流传的都是吴太医令吕广重新编纂的，文中多有错简（竹简顺序错乱），文辞意思难以明白。十七家的注解，如滑寿等人的仅存疑义，无法考证。或许还有古本，可惜未在世上显露。现在您听到的，莫非是吴太医令的古本吗？客人说不是。于是我偕同沈先生去拜访他，见到这个人，飘然若仙，白发苍苍，不是世俗之人。阅读他的书，也不是平时见过的书，才知道《难经》原本辞意明晓、道理贯通，没有一个字是多余的。所以苏轼在《楞伽跋》中说：“如同医家的《难经》，句句都有道理，字字都有法则。”必定是有见识的人才这么说，更加证实了我老师的话是有根据的。唉！两千多年来忽隐忽现的书籍，一旦重新显现，让天下人知道八十一难，是越人对《内经》的注释，而先生的文章，又疏解了越人的注释含义。这就好像中天之日，细微之处都照得清清楚楚。将看到这一版本一出，那么十七家的版本都可以废除了。先生成就了不朽的功业，难道是常人所能企及的吗？丁先生离席回答说：“河图洛书，因为圣人而出世，是世人秘藏的书，等待圣明的朝代才显现。这也是理数使然。我是什么人，敢参与这份功劳呢？”我因此乐于遇见这样的事并记录其事，恭敬地陈述在书末。
乾隆三年戊午阳月，洞庭菊坡居士严茂源书写。
The *Nan Jing* (Classic of Difficult Issues) is the essence of the *Ling Shu* and *Su Wen* (collectively known as the *Huang Di Nei Jing*, or Yellow Emperor's Inner Canon, foundational texts of Traditional Chinese Medicine). While the *Ling Shu* and *Su Wen* are often considered pseudonymous works, the *Nan Jing* is a book authored by hand by Bian Que. It inherits the wisdom of past sages and opens the way for future worthies, serving undoubtedly as the standard for the medical field. However, ancient texts have long been obscured, and versions circulating in the world contain many errors. Consequently, commentators have relied on subjective speculation, and readers have harbored doubts. Because the *Nan Jing* is obscure, the *Ling Shu* and *Su Wen* are not fully illuminated; and because the *Ling Shu* and *Su Wen* are not illuminated, the Way of Medicine might almost cease to exist.
Previously, I traveled to Wu Men (Suzhou) to seek medical knowledge, where I met a friend from She named Jin Zi, who presented me with an ancient edition of the *Nan Jing*. Upon reading it, the principles became clear and the details orderly; the pulse theories were connected, and the meridians integrated. Compared to the erroneous versions circulating in the world, it was like clearing away clouds and fog to behold the vast sky. Thus, I extensively examined various commentaries and proofread them item by item. No other volume possessed such clarity of text and precision of annotation as this one. I treasured it in my chest, brought it home, and planned to have it carved onto wooden blocks for printing, to share it with like-minded individuals. Fortunately, scholars who cherish antiquity enthusiastically supported this endeavor. Within a few months, the book was completed. This allowed a text that had been hidden and obscure for thousands of years to suddenly shine brightly throughout the realm. This is a fortune for the Way of Medicine, and indeed a great blessing for all those suffering from illness. Is this merit not magnificent? Therefore, I briefly outline its general history to record that I do not forget its source.
Preface by Zhang Ji of Jinxi, in the second month of the Gengshen year, the fifth year of the Jiaqing reign.
In my youth, I studied medicine and followed He Sizong, a gentleman from Yunjian, in my studies. Recently, having settled temporarily in Jin Chang (Suzhou), I frequently discussed medical classics with Wang Xiushen from Shangyang. The teachings of Nongxuan (referring to Shennong and Xuanyuan, symbolizing the origins of ancient medicine) are akin to the Six Classics (Confucian canonical texts); Bian Que and Zhang Zhongjing regarded Confucius as their spiritual master in the manner of Mengzi (Mencius). Therefore, the *Nan Jing* (Internal Difficulties) and the *Shang Han Lun* (Treatise on Cold Damage) constitute the three pillars of the medical gate. Since the Han dynasty, eminent scholars have emerged successively, relying solely on these three classics. Later authors, while making their own discoveries, gradually narrowed and shallowed their scope. This has led contemporary learners to prefer the superficial and fear the profound, pursuing trivialities while forgetting the root. Alas! If the meaning of the classics is not clarified, upon what can medical art rely? How can we find scholars who love antiquity to jointly discuss these three classics, citing the precedent of the Song Renzong era when medical books were collated, and petitioning the Sage Emperor to order Confucian officials and experts to consult ancient sources and adapt to modern needs, compile a complete work, and distribute it throughout the realm for the benefit of all generations?
Just then, a guest informed me: "The person previously thought to be hard to find has now been found." His surname is Ding, his style name Shilu. He brought an ancient edition of the *Nan Jing* from Rongcheng, added elucidations and annotations, and came to Wu to have it printed. Upon hearing this, I was initially surprised, then skeptical. I recalled my late teacher mentioning that during the Song Dynasty, Ding Deyou had annotated the *Nan Jing*: Hua Tuohua obtained the book of Yue Ren (Bian Que) but was captured, and the book was burned. What circulates today was recompiled by Lü Guang, the Imperial Physician of Wu, containing many disordered bamboo slips, making the language and meaning difficult to understand. Of the seventeen schools of commentary, such as that of Hua Shi (Slao Shou), only doubts remain, making verification impossible. Perhaps there are ancient editions, but they have unfortunately not been revealed to the world. Is what you heard about perhaps the ancient edition of Lü Guang? The guest said no. So I accompanied Mr. Shen to visit him. We saw a man, ethereal and white-haired, unlike worldly folk. Reading his book, which was not something I had seen before, I realized that the original *Nan Jing* has clear language and coherent logic, with not a single superfluous character. Thus, Su Dongpo wrote in his preface to the *Lenga Sutra*: "Like the medical *Nan Jing*, every sentence contains principle, and every word contains method." Only someone with true insight would say so, further confirming that my teacher's words had basis. Alas! A book that had been hidden and nearly lost for over two thousand years has suddenly reappeared, allowing people everywhere to know that the Eighty-One Difficulties are Yue Ren's commentary on the *Nei Jing*, and that Mr. Ding's writing further elucidates Yue Ren's commentary. It is like the sun in mid-heaven, illuminating even the finest details. Once this edition is published, the editions of the seventeen schools can be discarded. Mr. Ding has achieved immortal merit; is this within the reach of ordinary people? Mr. Ding rose from his seat and replied: "Hetu and Luoshu appeared because of the Sage; they are books kept secret by the world, waiting for a sage dynasty to be revealed. This is also due to the laws of reason and number. Who am I to dare claim credit for this?" I therefore rejoiced at this encounter and recorded the event, respectfully stating this at the end of the manuscript.
Written by Yan Maoyuan, Layman Ju Po of Dongting, in the tenth month of the Wuwu year, third year of the Qianlong reign.