六十五难曰∶经言所出为井，所入为合，其法奈何？然所出为井，井者东方春也，万物
之始生，故言所出为井也。所入为合，合者北方冬也，阳气入脏，故言所入为合也。
滑氏曰∶此以经穴之流注始终言也。
七十三难曰∶诸井者肌肉浅薄，气少不足使也，刺之奈何？然诸井者木也，荥者火也，
火
者木之子，当刺井者，以荥泻之。故经言补者不可以为泻，泻者不可以为补，此之谓也。
滑氏曰∶诸经之井，皆在手足指梢，肌肉浅薄之处，气少不足使为补泻也。故设当刺井
者，
只泻其荥，以井为木，荥为火，火者木之子也。详越人此说，专为泻井者言也，若当补井，
则必补其合，故引经言∶“补者不可以为泻，泻者不可以为补”，各有攸当也。补泻反则病
益笃，而有实实虚虚之患，可不谨哉。（武按∶滑氏谓经意为泻井而补，补井补合之言，端
自泻南方补北方意也。）
二十三难曰∶经脉十二，络脉十五，何始何穷也？然经脉者，行血气，通阴阳，以荥于
身者
也。其始从中焦注手太阴阳明，阳明注足阳明太阴，太阴注手少阴太阳，太阳注足太阳少阴
，少阴注手心主少阳，少阳注足少阳厥阴，厥阴复还注手太阴，别络十五，皆因其原，如环
无端，转相灌溉，朝于寸口人迎，以处百病，而决死生也。
滑氏曰∶因者随也，原者始也，朝犹朝会之朝，以用也。因上文经脉之尺度，而推言经
络之
行度也。直行者谓之经，旁出者谓之络，十二经有十二络，兼阳络阴络脾之大络，为十五络
也。谢氏曰∶始从中焦者，盖谓饮食入口藏于胃，其精微之化，注手太阴阳明，以次相传，
至足厥阴，厥阴复还注手太阴也。络脉十五，皆随十二经脉之所始，转相灌溉，如环之无端
，朝寸口人迎，以之处百病，而决死生也。寸口人迎，古法以侠喉两旁动脉为人迎，至晋王
叔和直以左手关前一分为人迎，右手关前一分为气口，后世宗之。愚谓昔人所以取人迎气口
者，盖人迎为足阳明胃经，受谷气而养五脏者也。气口为手太阴肺经，朝百脉而平权衡者也
。《此事难知》云∶寅手太阴肺，始于中焦，终于大指内廉出其端，卯手阳明大肠，始于手
大指次指之端，终于上侠鼻孔。辰足阳明胃，始于鼻交 中，终于入大指间出其端。已足太
阴脾，始于足大指之端，终于注心中。午手少阴心，始于心中，终于小指之内出其端。未手
太阳小肠，始于小指之端，终于抵鼻至目内 ，斜络于颧。申足太阳膀胱，始于目内 ，终
于小指内侧出其端。酉足少阴肾，始于小指之下，终于注胸中。戌手厥阴心包，始于胸中，
终于循小指次指出其端。亥手少阳三焦，始于小指次指之端终于目锐 。子足少阳胆，始于
目锐 ，终于小指次指内出其端，其支者上入大指岐骨内出其端，贯爪甲出三毛。丑足厥阴
肝，始于大指聚毛之上，终于注肺中。
《难经》第六十五问说：医经中说“所出为井，所入为合”，其中的法度是怎样的呢？回答说：所谓“所出为井”，井对应东方春季，是万物开始生长的时节，所以说“所出为井”。所谓“所入为合”，合对应北方冬季，阳气潜入脏腑，所以说“所入为合”。
《难经》第七十三问说：所有的井穴位于肌肉浅薄之处，经气少而不足以进行补泻操作，该如何针刺呢？回答说：所有的井穴属木，荥穴属火，火是木的子行，应当刺井穴时，通过泻其荥穴来进行治疗。所以医经说：“补法不可以当作泻法用，泻法不可以当作补法用”，说的就是这个道理。
滑寿（滑氏）说：各条经脉的井穴，都位于手足指端的梢部，即肌肉浅薄的地方，经气少而不足以作为补泻的操作基础。因此设定当刺井穴时，只泻其荥穴，因为井属木，荥属火，火是木的子行。详细考察越人（秦越人/扁鹊）的这个说法，专门是针对泻井穴而言的；如果应当补井穴，则必须补其合穴，所以引用医经的话说：“补者不可以为泻，泻者不可以为补”，各有其恰当的应用场合。补法和泻法如果用反了，病情会更加严重，从而产生“实其实、虚其虚”（使实证更实、虚证更虚）的祸患，怎能不谨慎呢？（高武按语：滑氏所说的经意在于泻井而补，以及补井补合的说法，确实源自“泻南方补北方”的理论意图。）
《难经》第二十三问说：十二经脉和十五络脉，从哪里开始，到哪里终结呢？回答说：经脉，是运行血气，沟通阴阳，以此滋养全身的组织。它们起始于中焦，注入手太阴肺经和手阳明大肠经；手阳明大肠经注入足阳明胃经和足太阴脾经；足太阴脾经注入手少阴心经和手太阳小肠经；手太阳小肠经注入足太阳膀胱经和足少阴肾经；足少阴肾经注入手厥阴心包经和手少阳三焦经；手少阳三焦经注入足少阳胆经和足厥阴肝经；足厥阴肝经又回流注入手太阴肺经。别络有十五条，都是顺着经脉的原穴起始点，像圆环一样没有端点，相互转输灌溉，汇聚于寸口和人迎穴，以此来诊治各种疾病，并判断生死预后。
滑寿（滑氏）说：“因”是随顺的意思，“原”是起始的意思，“朝”如同朝会之朝，表示运用。这是承接上文关于经脉尺度的论述，进而推演经络的运行度数。直行的称为经，旁出的称为络，十二经有十二条络脉，加上阳络、阴络以及脾之大络，共为十五条络脉。
谢氏说：起始于中焦，大概是指饮食入口藏于胃，其中精微物质的转化，注入手太阴肺经和手阳明大肠经，依次相传，直到足厥阴肝经，足厥阴肝经又回流注入手太阴肺经。十五条络脉，都随着十二经脉的起始点，相互转输灌溉，像圆环一样没有端点，汇聚于寸口和人迎，以此来诊治各种疾病，并判断生死预后。寸口和人迎，古法以咽喉两旁跳动的动脉为人迎穴，到了晋代王叔和直接以左手关前一分为人迎，右手关前一分为气口，后世都遵循这一做法。我认为古人之所以选取人迎和气口，是因为人迎属于足阳明胃经，受纳水谷之气以滋养五脏；气口属于手太阴肺经，朝会百脉以权衡气血盛衰。
《此事难知》记载：寅时手太阴肺经，始于中焦，终于大拇指内侧边缘出其端；卯时手阳明大肠经，始于食指次指（食指）的末端，终于上夹鼻孔处；辰时足阳明胃经，始于鼻翼交承浆处，终于进入大脚趾间出其端；巳时足太阴脾经，始于足大趾的末端，终于注入心中；午时手少阴心经，始于心中，终于小指内侧出其端；未时手太阳小肠经，始于小指的末端，终于抵达鼻子至目内眦，斜向联络于颧骨；申时足太阳膀胱经，始于目内眦，终于小指内侧出其端；酉时足少阴肾经，始于小趾之下，终于注入胸中；戌时手厥阴心包经，始于胸中，终于循行小指次指（无名指）出其端；亥时手少阳三焦经，始于小指次指的末端，终于目锐眦；子时足少阳胆经，始于目锐眦，终于小指次指内侧出其端，其支脉向上进入大脚趾歧骨内出其端，贯穿爪甲出于三毛处；丑时足厥阴肝经，始于大趾丛毛之上，终于注入肺中。
The sixty-fifth difficulty states: The classic texts say, "What emerges is the Jing-Well point, what enters is the He-Sea point." What is the method? The answer is: "What emerges is the Jing-Well point." The Jing-Well corresponds to the East and Spring, which is the beginning of the growth of all things; hence it is said that "what emerges is the Jing-Well point." "What enters is the He-Sea point." The He-Sea corresponds to the North and Winter, when Yang Qi enters the Zang organs; hence it is said that "what enters is the He-Sea point."
Master Hua (Hua Shou) says: This explains the beginning and end of the flow and distribution of acupoints along the meridians.
The seventy-third difficulty states: All Jing-Well points are located where muscles are shallow and thin, and the Qi is scarce and insufficient for tonification or sedation. How should they be needled? The answer is: All Jing-Well points belong to Wood, while Ying-Spring points belong to Fire. Fire is the child of Wood. When one needs to needle a Jing-Well point, one should sedate its corresponding Ying-Spring point. Thus, the classic texts state, "Tonification cannot be used as sedation, and sedation cannot be used as tonification," which refers to this principle.
Master Hua (Hua Shou) says: The Jing-Well points of all meridians are located at the tips of the fingers and toes, in areas where muscles are shallow and thin, and the Qi is scarce, making them unsuitable for direct tonification or sedation. Therefore, when it is necessary to needle a Jing-Well point, one should only sedate the Ying-Spring point. Since the Jing-Well belongs to Wood and the Ying-Spring belongs to Fire, and Fire is the child of Wood. A detailed examination of Yu Ren's (Bian Que's) statement reveals that it specifically addresses the sedation of Jing-Well points. If one needs to tonify a Jing-Well point, one must instead tonify its He-Sea point. Hence, the classic text is cited: "Tonification cannot be used as sedation, and sedation cannot be used as tonification," indicating that each has its appropriate application. If tonification and sedation are reversed, the disease will worsen, leading to the danger of "reinforcing excess and depleting deficiency" (making excess conditions more excessive and deficiency conditions more deficient). Can one not be cautious? (Gao Wu's note: Master Hua's interpretation regarding the sedation of Jing-Well points and tonification, as well as the tonification of Jing-Well and He-Sea points, indeed stems from the principle of "sedating the South and tonifying the North.")
The twenty-third difficulty states: There are twelve regular meridians and fifteen collaterals. Where do they begin and where do they end? The answer is: The meridians circulate Blood and Qi, connect Yin and Yang, and thereby nourish the body. They begin at the Middle Jiao and enter the Hand-Taiyin Lung Meridian and Hand-Yangming Large Intestine Meridian; the Hand-Yangming Large Intestine Meridian enters the Foot-Yangming Stomach Meridian and Foot-Taiyin Spleen Meridian; the Foot-Taiyin Spleen Meridian enters the Hand-Shaoyin Heart Meridian and Hand-Taiyang Small Intestine Meridian; the Hand-Taiyang Small Intestine Meridian enters the Foot-Taiyang Bladder Meridian and Foot-Shaoyin Kidney Meridian; the Foot-Shaoyin Kidney Meridian enters the Hand-Jueyin Pericardium Meridian and Hand-Shaoyang Sanjiao Meridian; the Hand-Shaoyang Sanjiao Meridian enters the Foot-Shaoyang Gallbladder Meridian and Foot-Jueyin Liver Meridian; the Foot-Jueyin Liver Meridian then returns to enter the Hand-Taiyin Lung Meridian. The fifteen collateral vessels all follow their Yuan-Source points, forming a circle without beginning or end, irrigating each other in rotation, and converging at the Cun Kou (Radial Artery) and Ren Ying (Carotid Artery) to diagnose various diseases and determine life and death.
Master Hua (Hua Shou) says: "Yin" means following, and "Yuan" means beginning. "Chao" is like a court audience, implying usage. This follows the previous discussion on the measurements of the meridians to deduce the course of the collaterals. Straight-running vessels are called meridians, and those branching off are called collaterals. There are twelve collaterals corresponding to the twelve meridians, plus Yang collaterals, Yin collaterals, and the Great Collateral of the Spleen, totaling fifteen collaterals.
Master Xie says: Beginning at the Middle Jiao implies that food enters the mouth and is stored in the Stomach. Its refined essences transform and enter the Hand-Taiyin Lung Meridian and Hand-Yangming Large Intestine Meridian, passing sequentially until the Foot-Jueyin Liver Meridian, which then returns to enter the Hand-Taiyin Lung Meridian. The fifteen collaterals all follow the beginnings of the twelve meridians, irrigating each other in rotation like a circle without end, converging at the Cun Kou and Ren Ying to diagnose diseases and determine life and death. Regarding Cun Kou and Ren Ying, ancient methods identified the Ren Ying as the pulsating artery beside the throat. However, Wang Shuhe of the Jin Dynasty directly designated the point one finger-breadth anterior to the cun guan on the left hand as Ren Ying, and the point one finger-breadth anterior to the cun guan on the right hand as Qi Kou. Later generations followed this practice. I believe the ancients selected Ren Ying and Qi Kou because Ren Ying belongs to the Foot-Yangming Stomach Meridian, receiving Grain Qi to nourish the five Zang organs; whereas Qi Kou belongs to the Hand-Taiyin Lung Meridian, overseeing the hundred vessels to weigh and balance them.
The book *Ci Nan Zhi Yi* records: At the hour of Yin (3–5 AM), the Hand-Taiyin Lung Meridian begins at the Middle Jiao and ends at the radial side of the thumb. At the hour of Mao (5–7 AM), the Hand-Yangming Large Intestine Meridian begins at the tip of the index finger and ends above the nostrils. At the hour of Chen (7–9 AM), the Foot-Yangming Stomach Meridian begins at the nose bridge and ends between the big toe. At the hour of Si (9–11 AM), the Foot-Taiyin Spleen Meridian begins at the tip of the big toe and ends by entering the Heart. At the hour of Wu (11 AM–1 PM), the Hand-Shaoyin Heart Meridian begins at the Heart and ends at the ulnar side of the little finger. At the hour of Wei (1–3 PM), the Hand-Taiyang Small Intestine Meridian begins at the tip of the little finger, reaches the nose and inner canthus, and obliquely connects to the cheekbone. At the hour of Shen (3–5 PM), the Foot-Taiyang Bladder Meridian begins at the inner canthus and ends at the medial side of the little toe. At the hour of You (5–7 PM), the Foot-Shaoyin Kidney Meridian begins below the little toe and ends by entering the chest. At the hour of Xu (7–9 PM), the Hand-Jueyin Pericardium Meridian begins in the chest and ends at the tip of the ring finger. At the hour of Hai (9–11 PM), the Hand-Shaoyang Sanjiao Meridian begins at the tip of the ring finger and ends at the outer canthus. At the hour of Zi (11 PM–1 AM), the Foot-Shaoyang Gallbladder Meridian begins at the outer canthus and ends at the medial side of the ring finger; its branch enters the space between the big toe bones and exits through the nail bed. At the hour of Chou (1–3 AM), the Foot-Jueyin Liver Meridian begins above the hair on the big toe and ends by entering the Lungs.