黄帝问于伯高曰。愿闻卫气之行。出入之合。何如。伯高曰。岁有十二月。日有十二辰。子午为经。卯酉为纬。天
周二十八宿。而一面七星。四七二十八星。房昴为纬。虚张为经。（张当是星）是故房至毕为阳。昴至心为阴。阳主昼。
阴主夜。故卫气之行一日一夜。五十周于身。昼日行于阳二十五周。夜行于阴二十五周。周于五脏是故平旦阴尽阳气出
于目。目张则气上行于头。循项。下足太阳。循背。下至小指之端。其散者。别于目锐 。下手太阳。下至手小指之间
外侧。其HT 者。别于目锐 。下足少阳。注小指次指之间。以上循手少阳之分侧下至小指之间。别者。以上至耳。前合
于颔脉。注足阳明。以下行。至跗上。入五指之间。其HT 者。从耳下。下手阳明。入大指之间。入掌中。其至于足也。
入足心。出内踝。下行阴分。复合于目。故为一周。（据此经义是手足三阳同时并行而又从足太阳足阳明同时并入于阴分
也三阳者阳经之部分也阴分者阴经之部分也）是故日行一舍。人气行一周与十分身之八。日行二舍。人气行三周于身与
十分身之六。日行三舍。人气行于身五周与十分身之四。日行四舍。人气行于身七周与十分身之二。日行五舍。人气行
于身九周。日行六舍。人气行于身十周与十分身之八。日行七舍。人气行于身十二周与十分身之六。日行十四舍。人气
二十五周于身。有奇分。与十分身之二。阳尽于阴。阴受气矣。其始入于阴。当从足少阴注于肾。肾注于心。心注于肺。
肺注于肝。肝注于脾。脾复注于肾为一周也。是故夜行一舍。人气行于阴脏一周与十分藏之八。亦如阳行之二十五周。
而复合于目。阴阳一日一夜。合有奇分十分身之二。与十分藏之二。是故。人之所以卧起之时有早晏者。奇分不尽故也。
黄帝曰。卫气之在于身也。上下往来不以期候气。而刺之奈何。（上衣冠文物叙有期矣此言不以期者上乃气所行之期此指气所
在之期以明刺法也气所行者手足六阳同时并出难专所在也气所在者气所最盛之部即气所往来交会之部也起处出入二字是
言身与脏气之内外也此来往二字是专言身气之上下也）伯高曰。分有多少。日有长短。春秋冬夏。各有分理。然后常以
平旦为纪。以夜尽为始。是故一日一夜。水下百刻。二十五刻者半日之度也。（昼日之半也一日一夜四分之）常如是。毋
已。日入而止。随日之长短。各以为纪而刺之。谨候其时。病可与期。失时反候。百病不治。故曰刺实者。刺其来也。
刺虚者。刺其去也。此言气存亡之时。以候虚实而刺之也。是故谨候气之所在而刺之。是谓逢时。病在于三阳。必候其
气。在于阳而刺之。病在于三阴必候其气在阴分。而刺之水下一刻。人气在太阳。水下二刻。人气在少阳。水下三刻。
人气在阳明。水下四刻。人气在阴分。水下五刻。人气在太阳。水下六刻。人气在少阳。水下七刻。人气在阳明。水下
八刻。人气在阴分。水下九刻。人气在太阳。水下十刻。人气在少阳。水下十一刻。人气在阳明。水下十二刻。人气在
阴分。水下十三刻。人气在太阳。水下十四刻。人气在少阳。水下十五刻。人气在阳明。水下十六刻。人气在阴分。水
下十七刻。人气在太阳。水下十八刻。人气在少阳。水下十九刻。人气在阳明。水下二十刻。人气在阴分。水下二十一
刻。人气在太阳。水下二十二刻。人气在少阳。水下二十三刻。人气在阳明。水下二十四刻。人气在阴分。水下二十五
刻。人气在太阳。此半日之度也。从房至毕。一十四舍。水下五十刻。日行半度。日行一舍。水下三刻与七分刻之四。（以
每刻十五分计之其七分之四当八分五七一四二而仍有奇分也五十营篇以下水四刻日行四十分是日行一舍又九分舍之一而
亦仍有奇分也故常以日加宿上即人气在太阳者特大略而已非密率也）大要曰。常以日之加于宿上也。人气在太阳。是故
日行一舍。人气行三阳及与阴分。（此句行字与前半篇行字不同然究未免相混）常如是无已。天地同纪。纷纷HT HT 。
终而复始。一日一夜。水下百刻而尽矣。（总以水刻为主者以其数相合而无奇零也）
言明且清气疏以达。妙在通篇实事。皆以议论行之。化板为活。举重若轻。是何等神勇。
篇中叙卫气行度。看似不合。故戴同甫。以水下一刻人气在太阳。以下为衍文。且谓当作一刻在三阳。二刻在三阴。
方符二刻一周之数。此得其一而未得其一也。经义前后本是两截。前叙卫气出于目。下足太阳。其散者。下手太阳。其
散者。下足少阳。上手少阳。其别者。下足阳明。其散者。下手阳明。又云。其至于足也。从足心入行阴分。是手足三
阳同时并行。本无分于先后。而又从足太阳足阳明同时并入行于阴分也。何有一刻太阳。二刻少阳。三刻阳明之事。更
何有待至四刻始行阴分之事。此戴氏一刻三阳。二刻三阴之说为不谬矣。然当云一刻行三阳。二刻行三阴。不当云在三
阳。在三阴也。后叙卫气之在身也。上下往来各有常期。乃是候其所在。而刺之又别一义。与前文全不相涉。刺法虽已
失传。而文义具在。澄心静思自能觑破。再所称手足太阳少阳阳明。皆以部分言。非以经络言也。阴分阳分统为昼行于
阳。内行五脏。乃为夜行于阴。
黄帝向伯高问道：我希望了解卫气在体内的运行规律，以及它出入阴阳的汇合情况，是怎样的呢？
伯高回答说：一年有十二个月，一天有十二个时辰。子时和午时是经线方向，卯时和酉时是纬线方向。天体环绕二十八星宿运行，每一面七星，四面共二十八星。房宿和昴宿构成纬线，虚宿和张宿构成经线。（这里的“张”指的是张宿）因此，从房宿到毕宿这一段属于阳，从昴宿到心宿这一段属于阴。阳主白天，阴主夜晚。所以卫气在人体内一昼夜运行五十周。白天行于阳分二十五周，夜晚行于阴分二十五周，并循环于五脏。
因此，清晨（平旦）阴气耗尽，阳气出于眼睛。眼睛睁开，气便上行至头部，沿着颈部，下行至足太阳膀胱经，沿着背部，下行至足小趾末端。其中散行的部分，从目外眦分出，下行至手太阳小肠经，下行至手小指外侧端。另一支散行的部分，从目外眦分出，下行至足少阳胆经，注入足第四趾与第五趾之间。以上行循行于手少阳三焦经的一侧，下行至手小指之间。又一支别行的，上行至耳前，与前方的颔脉相合，注入足阳明胃经，向下行，至足背，进入五指之间。另一支散行的，从耳下分出，下行至手阳明大肠经，进入大拇指之间，进入手掌中。当卫气到达足部时，进入足心，出于内踝，下行于阴分，最终重新会合于眼睛，这就完成了一周的运行。（根据此经文义，手足三阳经同时并行，并且又从足太阳、足阳明同时并入阴分。所谓“三阳”，是指阳经的部分；所谓“阴分”，是指阴经的部分。）
因此，太阳每运行经过一个星宿（舍），人气在体内运行一周加上身体长度的十分之八；太阳每运行经过两个星宿，人气在体内运行三周加上身体长度的十分之六；太阳每运行经过三个星宿，人气在体内运行五周加上身体长度的十分之四；太阳每运行经过四个星宿，人气在体内运行七周加上身体长度的十分之二；太阳每运行经过五个星宿，人气在体内运行九周；太阳每运行经过六个星宿，人气在体内运行十周加上身体长度的十分之八；太阳每运行经过七个星宿，人气在体内运行十二周加上身体长度的十分之六；太阳每运行经过十四个星宿，人气在体内运行二十五周，还有余数，即身体长度的十分之二。此时阳气尽于阴分，阴分接受了气。卫气刚开始进入阴分时，应当从足少阴肾经注入肾脏，由肾注入心脏，由心注入肺脏，由肺注入肝脏，由肝注入脾脏，由脾再注入肾脏，这就完成了一周的运行。
因此，夜晚太阳每运行经过一个星宿，人气在阴脏运行一周加上脏腑容量的十分之八，也像白天运行那样，总共二十五周，最后重新会合于眼睛。阴阳在一日一夜中，合起来有余数，分别是身体长度的十分之二，以及脏腑容量的十分之二。所以，人们睡觉起床的时间有早有晚，是因为这些余数不能完全整除的缘故。
黄帝说：卫气在体内上下往来，如果不按照固定的周期来候察卫气的位置，那么针刺该怎么做呢？（上文提到的“期”是指衣冠服饰等外在事物的固定规律，这里说的“不以期”是指不单纯依据外在固定规律，而是指卫气运行的周期。此处旨在说明针刺的方法。卫气运行之时，手足六阳经同时并出，难以确定其具体所在之处；而卫气所在之处，是指卫气最旺盛的部位，也就是卫气往来交会的部位。“起处”和“出入”二字，是说身体与内脏气的内外关系；这里的“来往”二字，是专指身体之气在上下之间的运行。）
伯高回答说：卫气分布有多有少，白昼黑夜有长有短，春秋冬夏四季，各有其不同的规律。然后通常以清晨为纪限，以夜尽天明为开始。因此，一昼夜漏水下百刻。二十五刻是半日的限度。（即一日一夜的四分之一）。通常如此，没有例外。日落时停止针刺，随着白昼长短的变化，各自作为纪限来进行针刺。必须谨慎地观察时机，疾病就可以预测并治疗。如果失去时机反而违背了规律，各种疾病就无法治愈。所以说，刺实证，要刺其气盛而来之时；刺虚证，要刺其气衰而去之时。这是说根据气的存亡时机，来候察虚实并进行针刺。
因此，必须谨慎地观察卫气所在的位置进行针刺，这叫做“逢时”。病在三阳经，必须候察其气在阳分时进行针刺；病在三阴经，必须候察其气在阴分时进行针刺。
漏水下第一刻，人气在足太阳膀胱经；水下第二刻，人气在足少阳胆经；水下第三刻，人气在足阳明胃经；水下第四刻，人气在阴分；水下第五刻，人气在足太阳膀胱经；水下第六刻，人气在足少阳胆经；水下第七刻，人气在足阳明胃经；水下第八刻，人气在阴分；水下第九刻，人气在足太阳膀胱经；水下第十刻，人气在足少阳胆经；水下第十一刻，人气在足阳明胃经；水下第十二刻，人气在阴分；水下第十三刻，人气在足太阳膀胱经；水下第十四刻，人气在足少阳胆经；水下第十五刻，人气在足阳明胃经；水下第十六刻，人气在阴分；水下第十七刻，人气在足太阳膀胱经；水下第十八刻，人气在足少阳胆经；水下第十九刻，人气在足阳明胃经；水下第二十刻，人气在阴分；水下第二十一刻，人气在足太阳膀胱经；水下第二十二刻，人气在足少阳胆经；水下第二十三刻，人气在足阳明胃经；水下第二十四刻，人气在阴分；水下第二十五刻，人气在足太阳膀胱经。这是半日的限度。
从房宿到毕宿，共十四个星宿，漏水下五十刻，太阳运行半周天。太阳每运行一个星宿，漏水下三刻又四分之七刻。（按每刻十五分计算，七分之四相当于八分五七一四二……仍有零头。《五十营》篇中提到水下四刻，日行四十分，是日行一个星宿又九分之一舍，也仍有零头。所以通常是将日期加在星宿上，即人气在太阳经者，只是大概而已，并非精确比率。）
大要说：通常根据太阳加临于星宿的情况，人气就在足太阳膀胱经。因此，太阳每运行一个星宿，人气运行于三阳经及阴分。（这个“行”字与前半篇的“行”字含义不同，但终究难免混淆。）像这样没有止境，天地遵循共同的规律，纷繁复杂，终而复始。一昼夜，漏水下百刻而结束。（总之以水刻为主，因为其数值相合而没有零头。）
这段文字阐明且清气疏达，妙在全篇叙述实事，皆以议论行之，化板滞为活泼，举重若轻，是何等神勇。
篇中叙述卫气运行度数，看似不合逻辑，所以戴同甫认为，“水下下一刻人气在太阳”以下的内容是衍文（后人误增的文字），并且认为应该改为“一刻在三阳，二刻在三阴”，才符合二刻一周的数目。这只是得其一方面而未得另一方面。经文前后原本是两个独立的部分。前面叙述卫气出于眼睛，下行足太阳，其散行者下手太阳，其散行者下足少阳，上手少阳，其别行者下足阳明，其散行者下手阳明，又说其至于足部时，从足心入行阴分。这是手足三阳同时并行，本无先后之分，而又从足太阳、足阳明同时并入行于阴分。哪里有一刻太阳、二刻少阳、三刻阳明的事情？更哪里有等待到第四刻才开始行于阴分的事情？戴氏所说的“一刻三阳，二刻三阴”的说法是不正确的。然而应该说“一刻行三阳，二刻行三阴”，而不应该说“在三阳，在三阴”。后面叙述卫气在身体里上下往来各有常期，乃是候察其所在位置而针刺，又是另一种意义，与前文全不相涉。虽然刺法已经失传，但文义俱在，澄心静思自然能看破。再所称的手足太阳、少阳、阳明，都是以部位而言，不是以经络而言。阴分和阳分统称为昼行于阳，内行五脏，乃是为夜行于阴。
Huangdi asked Bo Gao, saying: "I wish to hear about the movement of Wei Qi (Defensive Qi), and how it enters and exits, merging between Yin and Yang. What is the pattern?"
Bo Gao replied: "There are twelve months in a year, and twelve double-hours (Shichen) in a day. Zi and Wu hours form the meridian axis, while Mao and You hours form the latitude axis. The heavens revolve around the Twenty-Eight Lunar Mansions. Each quarter of the sky contains seven mansions, totaling twenty-eight. Fang and Mao mansions form the latitude lines; Xu and Zhang mansions form the meridian lines. (Here, 'Zhang' refers to the Zhang Mansion.) Therefore, from Fang to Bi belongs to Yang, and from Mao to Xin belongs to Yin. Yang governs the day, and Yin governs the night. Thus, Wei Qi circulates through the body fifty times in one day and night. During the day, it travels in the Yang aspect twenty-five times; at night, it travels in the Yin aspect twenty-five times, circulating among the Five Zang Organs.
Therefore, at dawn (Pingdan), when Yin energy is exhausted, Yang Qi emerges from the eyes. When the eyes open, Qi ascends to the head, follows the neck, descends along the Foot-Taiyang Bladder Meridian, runs down the back, and reaches the tip of the little toe. The dispersed branches diverge from the outer canthus of the eye, descend to the Hand-Taiyang Small Intestine Meridian, and reach the lateral side of the little finger. Another dispersed branch diverges from the outer canthus, descends to the Foot-Shaoyang Gallbladder Meridian, and pours into the space between the fourth and fifth toes. Ascending along the lateral aspect of the Hand-Shaoyang Sanjiao Meridian, it descends to the little finger. Another separate branch ascends to the ear, merges anteriorly with the mandibular pulse, pours into the Foot-Yangming Stomach Meridian, descends to the dorsum of the foot, and enters between the five toes. Another dispersed branch descends from the ear, goes to the Hand-Yangming Large Intestine Meridian, enters between the thumb and index finger, and enters the palm. When it reaches the feet, it enters the center of the sole, exits the medial malleolus, descends in the Yin aspect, and finally reunites with the eyes. This completes one cycle. (According to the meaning of this classic, the Three Yang meridians of the hands and feet run simultaneously and merge into the Yin aspect from the Foot-Taiyang and Foot-Yangming meridians at the same time. 'Three Yang' refers to the portions of the Yang meridians; 'Yin aspect' refers to the portions of the Yin meridians.)
Thus, as the sun moves through one lunar mansion (She), the vital Qi circulates once through the body plus 8/10 of the body's length. As the sun moves through two mansions, vital Qi circulates three times plus 6/10. As the sun moves through three mansions, vital Qi circulates five times plus 4/10. As the sun moves through four mansions, vital Qi circulates seven times plus 2/10. As the sun moves through five mansions, vital Qi circulates nine times. As the sun moves through six mansions, vital Qi circulates ten times plus 8/10. As the sun moves through seven mansions, vital Qi circulates twelve times plus 6/10. As the sun moves through fourteen mansions, vital Qi circulates twenty-five times, with an excess fraction equivalent to 2/10 of the body's length. At this point, Yang is exhausted in Yin, and Yin receives the Qi. Initially entering the Yin, it should flow from the Foot-Shaoyin Kidney Meridian into the Kidneys, from the Kidneys into the Heart, from the Heart into the Lungs, from the Lungs into the Liver, from the Liver into the Spleen, and from the Spleen back into the Kidneys, completing one cycle.
Thus, at night, as the sun moves through one mansion, vital Qi circulates once through the Yin Zang organs plus 8/10 of their capacity, similar to the daytime circulation of twenty-five cycles, finally reuniting with the eyes. In one day and night, Yin and Yang combined have excess fractions: 2/10 of the body's length and 2/10 of the Zang organ capacity. Therefore, the timing of people's waking and sleeping varies because these fractional parts do not divide evenly.
Huangdi said: "When Wei Qi moves up and down in the body, if we do not wait for its specific periodic arrival to observe it, how should we apply acupuncture?" (The 'period' mentioned earlier referred to fixed external markers like clothing; here, 'not waiting for a period' means not relying solely on fixed external markers but on the specific timing of Qi arrival. This clarifies acupuncture methods. When Qi is moving, the Six Yang meridians of the hands and feet emerge simultaneously, making it difficult to pinpoint a single location. The 'location' refers to where Qi is most abundant, i.e., where it converges and intersects. 'Origin' and 'entry/exit' refer to the internal-external relationship between body and Zang-Qi. 'Coming and going' specifically refers to the vertical movement of body Qi.)
Bo Gao replied: "The distribution of Qi varies in amount, and days and nights vary in length. Spring, Autumn, Winter, and Summer each have their own distinct patterns. Generally, we take dawn as the reference point and the end of the night as the start. One day and night equals one hundred water-clock beats (Ke). Twenty-five Ke represents half a day (one-quarter of a full day). This is constant without exception. Acupuncture stops at sunset. Following the length of the day, each serves as a reference for acupuncture. We must carefully observe the timing; then disease can be predicted and treated. Losing the timing or acting contrary to the pattern renders all diseases untreatable. Therefore, it is said: To treat Excess conditions, puncture when the Qi arrives; to treat Deficiency conditions, puncture when the Qi departs. This describes observing the presence and absence of Qi to determine Excess or Deficiency before puncturing.
Therefore, carefully observe where the Qi is located and puncture accordingly; this is called 'meeting the time.' If the disease is in the Three Yang meridians, wait until the Qi is in the Yang aspect to puncture. If the disease is in the Three Yin meridians, wait until the Qi is in the Yin aspect to puncture.
At the first Ke after midnight, Vital Qi is in the Foot-Taiyang [Bladder].
At the second Ke, Vital Qi is in the Foot-Shaoyang [Gallbladder].
At the third Ke, Vital Qi is in the Foot-Yangming [Stomach].
At the fourth Ke, Vital Qi is in the Yin aspect.
At the fifth Ke, Vital Qi is in the Foot-Taiyang [Bladder].
At the sixth Ke, Vital Qi is in the Foot-Shaoyang [Gallbladder].
At the seventh Ke, Vital Qi is in the Foot-Yangming [Stomach].
At the eighth Ke, Vital Qi is in the Yin aspect.
At the ninth Ke, Vital Qi is in the Foot-Taiyang [Bladder].
At the tenth Ke, Vital Qi is in the Foot-Shaoyang [Gallbladder].
At the eleventh Ke, Vital Qi is in the Foot-Yangming [Stomach].
At the twelfth Ke, Vital Qi is in the Yin aspect.
At the thirteenth Ke, Vital Qi is in the Foot-Taiyang [Bladder].
At the fourteenth Ke, Vital Qi is in the Foot-Shaoyang [Gallbladder].
At the fifteenth Ke, Vital Qi is in the Foot-Yangming [Stomach].
At the sixteenth Ke, Vital Qi is in the Yin aspect.
At the seventeenth Ke, Vital Qi is in the Foot-Taiyang [Bladder].
At the eighteenth Ke, Vital Qi is in the Foot-Shaoyang [Gallbladder].
At the nineteenth Ke, Vital Qi is in the Foot-Yangming [Stomach].
At the twentieth Ke, Vital Qi is in the Yin aspect.
At the twenty-first Ke, Vital Qi is in the Foot-Taiyang [Bladder].
At the twenty-second Ke, Vital Qi is in the Foot-Shaoyang [Gallbladder].
At the twenty-third Ke, Vital Qi is in the Foot-Yangming [Stomach].
At the twenty-fourth Ke, Vital Qi is in the Yin aspect.
At the twenty-fifth Ke, Vital Qi is in the Foot-Taiyang [Bladder]. This concludes the half-day cycle.
From the Fang Mansion to the Bi Mansion covers fourteen mansions. Water flows fifty Ke, and the sun moves half the celestial sphere. For every mansion the sun traverses, water flows three Ke and 7/15 of a Ke (approx. 0.857 Ke, with remainders). (Calculated by 15 fen per Ke, 7/15 is approx 8.57 fen... still with remainders. The 'Fifty Circulations' chapter mentions that at 4 Ke, the sun travels 40 fen, which is one mansion plus 1/9 of a She, also with remainders. Thus, generally adding the date to the mansion position—where Vital Qi is in Taiyang—is only an approximation, not a precise rate.)
The general principle states: Usually, based on the sun's position relative to the mansions, Vital Qi is in the Foot-Taiyang [Bladder]. Therefore, as the sun moves through one mansion, Vital Qi circulates through the Three Yang meridians and the Yin aspect. (The character 'circulate' here differs slightly from the earlier usage, though confusion remains inevitable.) Continue thus without end; Heaven and Earth follow the same rhythm, complex and endless, beginning and ending anew. One day and night, water flows one hundred Ke and finishes. (Water clocks are used as the primary measure because their numbers align without fractional remainders.)
This passage elucidates clear and pure Qi flowing smoothly. Its brilliance lies in narrating factual events through discursive reasoning, transforming rigidity into vitality, handling heavy matters with lightness. How divine and courageous is this!
The description of Wei Qi's movement in this chapter seems illogical. Therefore, Dai Tongfu considered the text following 'At the first Ke... Vital Qi is in Foot-Taiyang' as interpolations (later additions). He argued it should read 'One Ke in Three Yang, Two Ke in Three Yin' to fit the number of two Ke per cycle. This captures only one aspect. The classic's front and back sections were originally two separate parts. The front describes Wei Qi emerging from the eyes, descending Foot-Taiyang, its dispersed branches going to Hand-Taiyang and Foot-Shaoyang, ascending Hand-Shaoyang, its separate branch going to Foot-Yangming, its dispersed branch going to Hand-Yangming, and stating that upon reaching the feet, it enters the Yin aspect from the sole. This indicates the Three Yang meridians of hands and feet run simultaneously without sequence, merging into the Yin aspect from Foot-Taiyang and Foot-Yangming together. Where is there a sequence of 'One Ke Taiyang, Two Ke Shaoyang, Three Ke Yangming'? And where is there waiting until the fourth Ke to enter the Yin aspect? Dai's theory of 'One Ke Three Yang, Two Ke Three Yin' is incorrect. It should state 'One Ke circulates through Three Yang, Two Ke circulates through Three Yin,' not 'is in Three Yang/Yin.' The latter part describes Wei Qi moving up and down in the body with regular periods, which is about observing its location for acupuncture—a different meaning entirely unrelated to the previous text. Although the acupuncture method is lost, the textual meaning remains; with calm reflection, one can discern it. Furthermore, the references to Hand/Foot Taiyang, Shaoyang, and Yangming refer to anatomical regions/portions, not specific meridians. The Yin and Yang aspects collectively refer to daytime circulation in Yang (exterior) and nighttime circulation in Yin (interior/Zang organs)."