黄帝问于岐伯曰。经脉十二者。外合于十二经水。而内属于五脏六腑。夫十二经水者。其有大小深浅广狭远近。各
不同。五脏六腑之高下小大。受谷之多少。亦不等。相应奈何。夫经水者。受水而行之。五脏者。合神气魂魄而藏之。
六腑者。受谷而行之。受气而扬之。经脉者。受血而营之。合而以治奈何。刺之深浅。灸之壮数。可得闻乎。岐伯答曰。
善哉问也。天至高不可度。地至广不可量。此之谓也。且夫人生于天地之间。六合之内。此天之高。地之广也。非人力
之所度量而至也。若夫八尺之士。皮肉在此。外可度量切循而得之。其死可解剖而视之。其脏之坚脆。腑之大小。谷之
多少。脉之长短。血之清浊。气之多少。十二经之多血少气。与其少血多气。与其皆多血气。与其皆少血气。皆有大数。
其治以针艾。各调其经气。固其常有合乎。黄帝曰。余闻之。快于耳。不解于心。愿卒闻之。岐伯答曰。此人之所以参
天地而应阴阳也。不可不察。足太阳外合于清水。内属于膀胱。而通水道焉。足少阳外合于渭水。内属于胆。足阳明外
合于海水。内属于胃。足太阴外合于湖水。内属于脾。足少阴外合于汝水。内属于肾。足厥阴外合于渑水。内属于肝。
手太阳外合于淮水。内属于小肠。而水道出焉。手少阳外合于漯水。内属于三焦。手阳明外合于江水。内属于大肠。手
太阴外合于河水。内属于肺。手少阴外合于济水。内属于心。手心主外合于漳水。内属于心包。凡此五脏六腑十二经水
者。外有源泉而内有所禀。此皆内外相贯。如环无端。人经亦然。故天为阳。地为阴。腰以上为天。腰以下为地。故海
以北者为阴。湖以北者为阴中之阴。漳以南者为阳。河以北至漳者为阳中之阴。漯以南至江者为阳中之太阳。此一隅之
阴阳也。所以人与天地相参也。黄帝曰。夫经水之应经脉也。其远近浅深。水血之多少各不同。合而以刺之。奈何。岐
伯答曰。足阳明五脏六腑之海也。其脉大血多气盛热壮刺此者不深。弗散不留不泻也。足阳明刺深六分。留十呼。足太
阳深五分。留七呼。足少阳深四分。留五呼。足太阴深三分。留四呼。足少阴深二分。留三呼。足厥阴深一分。留二呼。
手之阴阳。其受气之道近。其气之来疾。其刺深者。皆无过二分。其留皆无过一呼。其少长大小肥瘦以心撩之。（言浅深
多少虽有定数又当揣人之少长肥瘦而意为增损之也）命曰法天之常。灸之亦然。灸而过此者。得恶火则骨枯脉涩。刺而
过此者则脱气。黄帝曰。夫经脉之小大。血之多少。肤之浓薄。肉之坚脆。及 之大小。可为量度乎。岐伯答曰。其可
为量度者。取其中度也。不甚脱肉而血气不衰也。若夫所度之人 瘦。而形肉脱者。恶可以度量刺乎。审切循扪按视其
寒温盛衰而调之是谓因适而为之真也。（此即所谓以心撩之也）
比经脉于经水。无甚深义。不过拟议远近。浅深多少之象数耳。后幅论刺法之浅深。及取穴之量度。词极圆活笔亦
生动。
Huangdi asked Qibo, saying: The twelve meridians of the body correspond externally to the twelve rivers and internally belong to the five zang organs and six fu organs. These twelve rivers vary in size, depth, width, narrowness, distance, and proximity, each being different. The positions, heights, sizes, and capacities for receiving grain and water of the five zang organs and six fu organs are also unequal. How do they correspond? The rivers receive water and flow; the five zang organs store the spirit, qi, hun, and po; the six fu organs receive grain and transmit it, accept qi and disperse it; the meridians receive blood and nourish the body. How should these be combined for treatment? May I ask about the depth of acupuncture and the number of moxibustion cones?
Qibo replied: Excellent question! Heaven is so high it cannot be measured; Earth is so vast it cannot be quantified. This is what is meant. Moreover, humans live between Heaven and Earth, within the Six Directions. The height of Heaven and the breadth of Earth are not fully measurable by human effort. However, for a person eight chi tall, the skin and flesh are on the surface, accessible to measurement and palpation; after death, anatomy can reveal them. The firmness or fragility of the zang organs, the size of the fu organs, the amount of grain received, the length of the vessels, the clarity or turbidity of the blood, the quantity of qi, and whether the twelve meridians have much blood and little qi, little blood and much qi, both much blood and qi, or both little blood and qi—all have general fixed numbers. When treating with needles and moxa, one regulates the meridian qi accordingly, which must follow common principles.
Huangdi said: I hear this with pleasure, but my mind does not yet understand. I wish to hear the complete explanation.
Qibo answered: This is how humans participate in Heaven and Earth and respond to Yin and Yang; it must be carefully examined. Foot-Taiyang corresponds externally to the Qingshui River and internally to the Bladder (Pangguang), governing the water passages. Foot-Shaoyang corresponds externally to the Weishui River and internally to the Gallbladder (Dan). Foot-Yangming corresponds externally to the Haiwater (Ocean) and internally to the Stomach (Wei). Foot-Taiyin corresponds externally to the Hushui Lake and internally to the Spleen (Pi). Foot-Shaoyin corresponds externally to the Rushui River and internally to the Kidney (Shen). Foot-Jueyin corresponds externally to the Mianshui River and internally to the Liver (Gan). Hand-Taiyang corresponds externally to the Huaishui River and internally to the Small Intestine (Xiaochang), from which water passages exit. Hand-Shaoyang corresponds externally to the Luoshui River and internally to the Sanjiao (Triple Burner). Hand-Yangming corresponds externally to the Jiangshui River and internally to the Large Intestine (Dachang). Hand-Taiyin corresponds externally to the Heshui River and internally to the Lung (Fei). Hand-Shaoyin corresponds externally to the Jishui River and internally to the Heart (Xin). Hand-Jueyin (Pericardium) corresponds externally to the Zhangshui River and internally to the Pericardium (Xinbao). All these five zang and six fu organs corresponding to the twelve rivers have external sources and internal endowments. They are interconnected like a circle without beginning or end. Human meridians are the same. Thus, Heaven is Yang, Earth is Yin; above the waist is Heaven, below the waist is Earth. Therefore, areas north of the sea are Yin; areas north of lakes are Yin within Yin; areas south of the Zhang River are Yang; areas north of the Yellow River up to the Zhang River are Yin within Yang; areas south of the Luo River up to the Yangtze are Taiyang within Yang. This is merely a partial illustration of Yin and Yang, showing how humans correspond to Heaven and Earth.
Huangdi asked: Regarding the correspondence between rivers and meridians, their distances, depths, and the amounts of water and blood differ. How should acupuncture be applied considering these differences?
Qibo replied: Foot-Yangming is the Sea of the Five Zang and Six Fu organs. Its vessel is large, with abundant blood and vigorous Qi, characterized by strong heat. If needling this meridian is not deep enough, pathogenic factors will not dissipate, stagnation will not remain, and excess will not be drained. Therefore, for Foot-Yangming, the needle depth is six fen, retained for ten breaths. For Foot-Taiyang, depth is five fen, retained for seven breaths. For Foot-Shaoyang, depth is four fen, retained for five breaths. For Foot-Taiyin, depth is three fen, retained for four breaths. For Foot-Shaoyin, depth is two fen, retained for three breaths. For Foot-Jueyin, depth is one fen, retained for two breaths. For the Hand Yin and Yang meridians, the pathway for receiving Qi is closer, and Qi movement is rapid. Thus, even the deepest needling should not exceed two fen, and retention should not exceed one breath. For individuals of different ages, sizes, fatness, or thinness, one must mentally assess and adjust. (This means that although there are fixed standards for depth and quantity, adjustments must be made based on whether the patient is young or old, tall or short, fat or thin.) This is called following the constant laws of Heaven. Moxibustion follows the same principle. If moxibustion exceeds these limits, "evil fire" may occur, leading to dry bones and sluggish pulses. If needling exceeds these limits, Qi depletion may result.
Huangdi asked: Can the size of meridians, amount of blood, thickness of skin, firmness of muscle, and size of collaterals serve as standards for measurement?
Qibo replied: Those that can be measured should use the average-sized person as the standard—specifically, those who are not emaciated and whose blood and Qi are robust. As for those who are extremely thin and emaciated, how can fixed measurements for needling be applied? One must carefully palpate, touch, press, and observe the cold, heat, excess, and deficiency to regulate the condition. This is called establishing true treatment based on appropriateness. (This refers to the previously mentioned "mental assessment.")
Comparing meridians to rivers carries no profound meaning; it merely uses imagery and numerical analogies for distance, depth, and quantity. The latter part discusses the depth of needling and the measurement of acupoint selection. The language is highly flexible, and the writing style is vivid.