黄帝问于岐伯曰。余闻针道于夫子。众多毕悉矣。夫子之道应若失。而据未有坚然者也。夫子之问学熟乎。将审察
于物而心生之乎。（言用针之应与失未有确然先见之据也而能无失者此由于问学之熟乎抑随时审物而心生之乎下乃两答
之也）岐伯曰。圣人之为道者。上合于天。下合于地。中合于人事。必有明法。以起度数。法式检押。乃后可传焉。故
匠人不能释尺寸而意短长。废绳墨而起平直也。工人不能置规而为员。去矩而为方知用此者。固自然之物易用之。教逆
顺之常也。（言此乃自然之事易晓之说针道得失之常也）黄帝曰。愿闻自然奈何。岐伯曰。临深决水。不用功力。而水可
竭也。循掘决冲。而经可通也。此言气之滑涩。血之清浊。行之逆顺也。（此逆顺指气之来往与上文异）黄帝曰。愿闻人
之白黑肥瘦小长。各有数乎。岐伯曰。年质壮大。血气充盈。肤革坚固。因加以邪。刺此者。深而留之。此肥人也。广
肩腋。项肉薄。浓皮而黑色。唇临临然。其血黑。以浊其气涩。以迟其为人也。贪于取与。刺此者。深而留之。多益其
数也。黄帝曰。刺瘦人奈何。岐伯曰。瘦人者。皮薄色少。肉廉廉然。薄唇轻言。其血清。气滑易脱于气。易损于血。
刺此者浅而疾之。黄帝曰。刺常人奈何。岐伯曰。视其白黑。各为调之。其端正敦浓者。其血气和调。刺此者无失常数
也。黄帝曰。刺壮士真骨者奈何。岐伯曰。刺壮士真骨。坚肉缓节监监然。此人重。则气涩血浊。刺此者。深而留之。
多益其数。劲则气滑血清。刺此者。浅而疾之。（重骨体浓重也劲骨体轻捷也）黄帝曰。刺婴儿奈何。岐伯曰。婴儿者其
肉脆。血少气弱。刺此者。以豪针。浅刺而疾发针。日再可也。黄帝曰。临深决水奈何。岐伯曰。血清气滑。疾泻之则
气竭焉。黄帝曰。循掘决冲奈何。岐伯曰。血浊气涩。疾泻之则经可通也。黄帝曰脉行之逆顺奈何。岐伯曰。手之三阴。
从脏走手。手之三阳。从手走头。足之三阳。从头走足。足之三阴。从足走腹。黄帝曰。少阴之脉独下行。何也。岐伯
曰。不然。夫冲脉者。五脏六腑之海也。五脏六腑皆禀焉。其上者。出于颃颡。渗诸阳。灌诸精。其下者。注少阴之大
络。出于气街。循阴股内廉。入 中。伏行 骨内。下至内踝之后属而别。（属所也言内踝后之处所也）其下者。并于少
阴之经。渗三阴。其前者。伏行出跗属。下循跗。入大趾间。渗诸络而温肌肉。故别络结。则跗上不动。不动则厥。厥
则寒矣。黄帝曰。何以明之。岐伯曰。五官导之。（五官二字误据经意当是循而二字）切而验之。其非必动。（非邪气也
经脉曰脉之卒然动者皆邪气居之）然后乃可明逆顺之行也。黄帝曰。窘乎哉圣人之为道也。明于日月。微于毫厘。其非
夫子。孰能道之也。
此篇论刺法之逆顺。外视其人之肥瘦。内视经脉之行度也。法有坚据。因人而施。篇法整齐。词旨清畅。言针道所
以无失者。由于问学之熟。而临诊又须审物生心也。两层串说。
Huangdi asked Qibo: I have learned the principles of acupuncture from you, and they are comprehensive. However, when applying needle techniques, I feel that sometimes the response is accurate and sometimes it fails; I have not yet found a firm basis for consistent accuracy. Is this because your mastery comes from diligent study? Or does it arise from carefully observing phenomena and generating insights in your mind? (This passage means that there is no predetermined certainty in whether needle application will succeed or fail. To avoid errors, is it due to proficiency in learning, or to intuitive judgment generated by constantly examining objects? The following text answers these two questions separately.)
Qibo replied: The Dao practiced by sages aligns with Heaven above, Earth below, and human affairs in between. There must be clear laws to establish standards and norms. Only through models and constraints can these teachings be transmitted. Therefore, a carpenter cannot abandon measurements to guess lengths arbitrarily, nor discard the ink line to achieve straightness; a craftsman cannot dispense with the compass to draw circles, nor remove the square to draw rectangles. Those who understand how to use these tools do so because they are natural instruments, easy to use, teaching the constants of reversal and compliance. (This passage means that these are natural matters, easy to understand principles, and the common rules regarding the success or failure of acupuncture.)
Huangdi said: I wish to hear about "natural" principles.
Qibo said: When diverting water from a deep abyss, little effort is required, and the water can be drained; when breaking through obstacles along an excavated channel, the meridians can be unblocked. This illustrates the slipperiness or sluggishness of Qi, the clarity or turbidity of Blood, and the reverse or forward direction of their flow. (Here, "reverse and forward" refers to the movement of Qi, which differs from the previous context.)
Huangdi said: I wish to know if people's skin color (dark/light), body type (fat/thin), and stature (tall/short) each have specific characteristics.
Qibo said: If a person is young and strong, with abundant Qi and Blood, and tough, solid skin and flesh, and is additionally affected by pathogenic factors, such individuals should be needled deeply and retained. This applies to obese persons. They have broad shoulders and axillae, thin neck muscles, thick dark skin, and full, drooping lips. Their Blood is dark and turbid, and their Qi is sluggish and slow. Such individuals tend to be greedy in giving and taking. When needling them, one should needle deeply, retain the needles, and increase the number of sessions.
Huangdi said: How should emaciated persons be needled?
Qibo said: Emaciated persons have thin skin, pale complexion, lean muscles, thin lips, and speak softly. Their Blood is clear, and their Qi is slippery and prone to dispersion, making them easily damaged in terms of Blood. When needling them, one should needle shallowly and withdraw quickly.
Huangdi said: How should normal persons be needled?
Qibo said: Adjust according to their skin color and other features. For those who are upright and dignified, their Qi and Blood are harmonious. When needling them, do not deviate from standard parameters.
Huangdi said: How should robust persons with solid bones be needled?
Qibo said: For robust persons with solid bones, if their flesh is hard but joints are loose and their body is heavy, their Qi is sluggish and Blood is turbid. Needle them deeply, retain the needles, and increase the number of sessions. If their constitution is vigorous and bones light, their Qi is slippery and Blood is clear. Needle them shallowly and withdraw quickly. ("Heavy" refers to a dense physique; "Vigorous" refers to a agile physique.)
Huangdi said: How should infants be needled?
Qibo said: Infants have fragile flesh, scant Blood, and weak Qi. Use fine needles (Haonong), needle shallowly, and withdraw quickly. Treatment twice a day is acceptable.
Huangdi said: What does "diverting water from a deep abyss" mean?
Qibo said: For persons with clear Blood and slippery Qi, rapid draining methods will lead to depletion of Qi.
Huangdi said: What does "breaking through obstacles along an excavated channel" mean?
Qibo said: For persons with turbid Blood and sluggish Qi, rapid draining methods can unblock the meridians.
Huangdi said: What is the reverse and forward flow of the vessels?
Qibo said: The three Yin meridians of the hand travel from the Zang organs to the hands; the three Yang meridians of the hand travel from the hands to the head; the three Yang meridians of the foot travel from the head to the feet; the three Yin meridians of the foot travel from the feet to the abdomen.
Huangdi said: Why does the Shaoyin meridian alone descend?
Qibo said: Not so. The Chong Mai (Penetrating Vessel) is the Sea of the Five Zang and Six Fu organs; all organs receive its influence. Its ascending branch emerges from the pharynx, seeps into the Yang meridians, and nourishes the essences. Its descending branch pours into the large collateral of the Foot-Shaoyin Kidney Meridian, emerges at the Qichong (ST30) point, runs along the medial aspect of the thigh, enters the popliteal fossa, travels hidden within the bone, descends to behind the medial malleolus, and branches off there. (The term "Shu" refers to the location, meaning the area behind the medial malleolus.) The descending branch merges with the Foot-Shaoyin Meridian, seeps into the Three Yin meridians; its anterior branch travels hidden, emerges at the dorsum of the foot, runs down the dorsum, enters the space between the big toe, seeps into the collateral vessels, and warms the muscles. Therefore, if the collateral vessels are obstructed, the pulse on the dorsum of the foot will not move; if it does not move, Jue syndrome occurs, resulting in coldness.
Huangdi said: How can this be demonstrated?
Qibo said: It can be verified by palpation. (The characters "Wu Guan" [Five Organs] in the original text are erroneous; based on the context, they should be "Xun Er" [Follow and].) Palpate and examine; sudden movements in the pulse indicate the presence of pathogenic factors. (Abnormal pulsations are caused by pathogens occupying the meridians.) Only then can the reverse and forward flow of the vessels be clarified.
Huangdi said: The Dao mastered by sages is truly profound! It is as bright as the sun and moon, and as subtle as a hair's breadth. Without you, who could explain it so clearly?
This chapter discusses the reverse and forward aspects of needling techniques, observing external body types (fat/thin) and internal meridian flows. The methods have firm bases and are applied individually. The structure is neat, and the language is clear and fluent. It states that the reason acupuncture avoids error lies in proficiency in learning, while clinical practice requires examining phenomena and generating insight. These two layers are discussed sequentially.