【纲】仲景曰。伤寒脉浮而缓。手足自温者。系在太阴。太阴当发身黄。若小便自利者。不能
发黄。至六七日。虽暴烦。下利日十余行。必自止。以脾家实。腐秽当去故也。
【目】朱肱曰。足太阴脾之经。为三阴之首。其脉布于脾胃。络于嗌喉。故病患腹满而嗌干。
尺寸俱沉细者。知太阴经受病也。伤寒四五日。腹满咽干手足自温。或下利不渴。或腹满时痛。尺
寸脉俱沉细。此足太阴脾经受病也。伤寒手足必微冷。若手足自温者。系太阴也。自利不止。属太
阴也。腹满时痛。属太阴也。自利不渴者。脏寒也。当温之。宜四逆汤、理中汤也。腹满脉浮者。
可桂枝微发汗。腹痛者。桂枝加芍药汤。甚者。桂枝加大黄汤。
魏荔彤曰。脉浮缓。手足温。此近太阳中风。而手足不能发热。则脾脏素有湿邪。与风寒变热
之邪相溷。所以不能作大热于外。而实蓄深热于内。明其系在太阴。身当发黄。同于太阳发黄等症。
蓄热于里之义也。若小便利。湿泄而热去。故不能发黄。在阳明篇已言之。重见于此者。彼以太
阳初入阳明者言。其脾素有湿。则不能成胃实。表邪热入。止为发黄症。盖胃实本津液内竭。盛热
成实之症。既有湿邪。亦津液也。故不成胃实而成发黄。迨七八日热邪久已耗液。故复成胃实。以
大便硬为验。仲师于彼。指之为阳明病。起见与太阴病迥不同也。此条亦由太阳初入。然病终不归
阳明。故仲师指出太阴脾家实。当风寒变热传入。特以脾素湿。则邪热之投湿如烟投水。俱趋于脾
而为患也。故不能发黄。以上均于阳明所言同。但此至七八日。不惟大便不硬。却暴烦下利日十余
行者。病之初入同。病之去向分也。热胜湿。遂成胃实便硬。湿胜热。湿留而热欲去。遂成脾实下
利。此胃实脾实之分关。不出湿热二字也。湿。阴邪
凝滞。可以留。热阳邪迅捷。必欲出。小便既泄不尽。又不发黄。热从何出。必随湿下流。归于大
便。平日为泄为热所停蓄腐秽之物。无不随之而去。有不容自已之势也。此脾实系太阴。胃实属阳
明。止在湿热分关。遂为两经判然之症也。至二条俱未出方。盖阳明则胃实。宜四承气随人调剂。
太阴则脾实下利。未利前。如何除湿燥土。既利后。如何补中益脾。或兼除湿清热。又在人审量焉。
且使腐秽一泻得愈。亦可不必方治矣。
喻昌曰。太阴脉本缓。故浮缓虽类太阳中风。然手足自温。则不似太阳之发热。更不似少阴厥阴
之四逆与厥。所以系在太阴。不能发黄。以上与阳明篇中语句皆同。但彼以胃实而便硬。其症复转
阳明。此以脾实而下秽腐。其症止属太阴耳。至七八日暴烦下利。日十余行。其症又与少阴无别。
而腐秽尽。利当自止。则不似少阴之烦躁有加。下利漫无止期也。况少阴之烦而下利。手足反温。
脉紧反去者。仍为欲愈之候。若不辨析。误以四逆法治之。反增危矣。
【纲】仲景曰。伤寒下利。日十余行。脉反实者死。
【目】虞抟曰。脾气虚而邪气盛。故脉反实也。
【纲】仲景曰。太阴病。脉弱。其人续自便利。设当行大黄、芍药。宜减之。以其胃气弱。易
动故也。
【目】喻昌曰。此段叮咛。与阳明篇中互发。阳明曰不转失气。曰先硬后溏。曰未定成硬。皆
是恐伤太阴脾气。此曰脉弱便利。减用大黄、芍药。又恐伤阳明胃气也。
【纲】仲景曰。恶寒。脉微。而复利。亡血也。四逆加人参汤主之。
【目】朱肱曰。病有无热恶寒者。发于阴也。发于阴者。宜温里。脉必微。或沉细。属四逆加
人参汤、四逆汤、理中汤也。若发热微恶寒者。属柴胡桂枝汤也。
鳌按。以其恶寒未罢。故宜四逆。以其脉微为无血。故宜加人参。
【纲】仲景曰。太阴病。脉浮者。可发汗。宜桂枝汤。
【目】朱肱曰。问古人以四日太阴症发。病在胸膈。可吐而愈。何也。答曰。不然。有太阴症。
脉大胸满多痰者。可吐之。脉大而无痰症者。可汗而已。大抵在表者汗之。在里者下之。在上者
涌之。在下者泄之。瓜蒂栀豉。随症施用。不可以日数拘也。
魏荔彤曰。邪自太阳。而阳明。而少阳。递及太阴。法当还升之少阳。使由少阳之半表。透太
阳之表。亦兼在阳经之治也。太阴病而脉不沉缓。却见浮。则传入阴经之邪。复思远阳而去也。可
急发汗。俾得外越。而病可已矣。在太阳麻黄为发汗。桂枝为解肌。此言桂枝发汗。非发汗即解肌
也。盖用桂枝汤中芍药。引桂姜之辛温入阴分。而驱传入之邪。所谓阳因阴用也。且桂芍俱能走肝。
更可引太阴之邪。由少阳传入者。还回少阳而出。此桂枝汤但见太阴脉浮即可汗。未可拘风因用
桂枝。寒因用麻黄之说也。邪在太阳阳明。尚分风寒两因之来路。及由阳明而少阳。已不可复分。
更传太阴。岂能分风因寒因哉。再者。麻黄汤一概辛热。不能入阴分。即寒因可辨。亦不宜用。兼
之无隔少阳而驱入太阳之理。麻黄汤之力。但轻清上升。达于太阳。亦不能假少阳之道也。故不言
麻黄汤。非漏也。亦非举桂枝以概之也。知此则太阴邪之出路。必由少阳以返太阳。而他说俱不足以
惑之矣。
麻黄汤之走阴分。在营血则能入。以在太阳之表。入三阴之阴分。则不能入。以其升而不降也。
此亦宜知。
【纲】仲景曰。太阴中风。四肢烦疼。阳微阴涩而长者。为欲愈。
【目】方中行曰。四肢烦疼者。脾主四肢。亦风淫末疾之明验也。
魏荔彤曰。脉见长则邪自太阴欲还复少阳必矣。脾为脏里。经邪内陷。则症见腹满痛。吐不能
食等症。若经邪欲外出。则症见于四末。而不久于内陷可知矣。于是阳微阴涩。邪已有浸浸透至营
卫之势。兼以弦长。见少阳之门户辟。
而生发之气已动矣。更得四末之间。蠢然烦疼。汗出发热。其邪纯回太阳矣。邪不由太阳而去。乌
能自止乎。
【纲要】张仲景说：伤寒病，脉象浮而缓，手足自然温暖，这是病邪关联在太阴经。太阴病应当出现身体发黄的症状；如果小便通畅自如，就不会发黄。到了第六七天，虽然突然感到烦闷，并且每天腹泻十几次，但腹泻必定会自行停止。这是因为脾家正气恢复（脾家实），体内腐败秽浊之物应当排出的缘故。
【目次】朱肱说：足太阴脾经，是三阴经的首位。它的经脉分布于脾胃，联络咽喉。所以病人出现腹部胀满且咽喉干燥，寸口和尺口的脉搏都呈现沉细之象，可知是太阴经受邪致病。伤寒病四五天后，出现腹部胀满、咽喉干燥、手足自然温暖，或者腹泻但不口渴，或者腹部胀满并伴有间歇性疼痛，寸口和尺口的脉搏都沉细，这是足太阴脾经受邪致病。伤寒病通常手足会轻微发冷，如果手足自然温暖，就是病在太阴。如果是自发性腹泻不止，属于太阴病。如果是腹部胀满且间歇性疼痛，属于太阴病。自发性腹泻且不口渴，是因为内脏虚寒。应当采用温法治疗，适宜使用四逆汤或理中汤。如果腹部胀满且脉象浮，可以用桂枝汤轻微发汗。如果腹痛，用桂枝加芍药汤。病情严重的，用桂枝加大黄汤。
魏荔彤说：脉象浮缓，手足温暖，这接近于太阳中风证，但手足不能发热，说明脾脏素有湿邪，与风寒转化成的热邪混杂在一起。因此不能在体表产生大热，但实际上在体内蓄积了深重的热邪。明确其病系在太阴，身体应当发黄，这与太阳病发黄等症相同，都是热邪蓄积在里的含义。如果小便通利，湿气排出而热邪随之而去，所以不会发黄。这在阳明篇中已经论述过，这里再次提及，是因为阳明篇讲的是太阳初入阳明的情况。如果脾脏素来有湿，就不能形成胃家实证。表邪的热气传入，只会导致发黄症。所谓胃家实证，本是津液在内枯竭，盛热导致腑实而成的病症。既然有湿邪，湿也是津液的一种，所以不能形成胃家实证，而是形成发黄症。等到七八天，热邪长久耗伤津液，所以又形成了胃家实证，以大便坚硬作为验证。张仲景在那裡将其指为阳明病，其起因与太阴病截然不同。这一条也是由太阳初入引起，但病终不归入阳明，所以张仲景指出这是太阴脾家实证。当风寒转化为热邪传入时，特别因为脾脏素来有湿，邪热投入湿中就像烟投入水中，都趋向于脾而为患。所以不会发黄。以上观点均与阳明篇所言相同。但是到这里七八天时，不仅大便不硬，反而突然烦闷，腹泻每天十几次，这是病初传入时相同，但病的去向不同。热胜湿，就形成胃家实证和大便硬；湿胜热，湿留滞而热欲去，就形成脾家实证和下利。这是胃家实证和脾家实证的区分关键，不出“湿热”二字。湿是阴邪，凝滞，可以留滞；热是阳邪，迅捷，必然要外出。小便既然排泄不尽，又不发黄，热从哪里出去？必然随着湿向下流，归于大便。平日因泄泻被热邪停蓄的腐败秽浊之物，没有不随之而去的，有一种不容自己控制的气势。这就是脾家实证属于太阴，胃家实证属于阳明，仅仅在湿热的区分关键上，就成为两经截然不同的症状。至于这两条都没有给出方剂，大概是因为阳明病则是胃家实证，适宜根据具体情况调剂使用四种承气汤；太阴病则是脾家实证下利，在未利之前，如何除湿燥土？既已利后，如何补中益脾？或者兼除湿清热，又需要根据医者审量而定。况且如果使腐败秽浊之物一泻而愈，也可以不必用药治疗了。
喻昌说：太阴脉本应缓，所以浮缓虽然类似太阳中风，但手足自然温暖，就不像太阳病的发热，更不像少阴、厥阴的四肢逆冷与厥逆。所以病系在太阴。不能发黄，以上观点与阳明篇中的语句都相同。只是阳明篇是以胃家实证而大便硬，其症状又转属阳明；这里是以脾家实证而下出秽浊腐物，其症状只属于太阴罢了。到了七八天突然烦闷下利，每天十几次，其症状又与少阴病没有区别，但如果腐败秽浊之物排尽，腹泻应当自行停止，这就不同于少阴病的烦躁加重，下利漫无止期。何况少阴病的烦闷而下利，如果手足反而温暖，脉紧反而消失，仍然是将要痊愈的征候。如果不加以辨析，误用四逆法治之，反而会增加危险。
【纲要】张仲景说：伤寒病下利，每天十几次，脉象反而实大有力的，主死。
【纲要】张仲景说：太阴病，脉象弱，其人持续自行便利。假设应当使用大黄、芍药，应当减量。因为他的胃气虚弱，容易动扰的缘故。
【目次】喻昌说：这段叮咛嘱咐，与阳明篇中互相阐发。阳明篇说不转失气，说先硬后溏，说未定成硬，都是恐怕损伤太阴脾气。这里说脉弱便利，减用大黄、芍药，又是恐怕损伤阳明胃气。
【纲要】张仲景说：恶寒，脉微，并且又腹泻，这是亡血。用四逆加人参汤主治。
【目次】朱肱说：有病无发热而恶寒的，发于阴经。发于阴经的，适宜温里。脉象必定微细，或沉细，属于四逆加人参汤、四逆汤、理中汤的适应证。如果有发热且轻微恶寒的，属于柴胡桂枝汤的适应证。
沈金鳌按：因为恶寒尚未罢止，所以适宜用四逆汤。因为脉微表示无血，所以适宜加人参。
【纲要】张仲景说：太阴病，脉象浮的，可以发汗，适宜用桂枝汤。
【目次】朱肱说：问古人关于第四天太阴症发作，病在胸膈，可以用吐法而愈，为什么？回答说：不对。有太阴症，脉大且胸满多痰的，可以用吐法。脉大而没有痰症的，可以用汗法而已。大抵病在表的用汗法，病在里的用下法，病在上的用涌吐法，病在下的用泄下法。瓜蒂散、栀子豉汤，随症状施用，不可以拘泥于日数。
魏荔彤说：邪气从太阳，传到阳明，再传到少阳，依次及于太阴，治法应当使其还升于少阳，使由少阳的半表半里，透达至太阳之表，这也兼有治疗阳经的方法。太阴病而脉不沉缓，却见浮脉，则传入阴经的邪气，又想远离阳气而外出。可以紧急发汗，使得邪气外越，病就可以好了。在太阳病中，麻黄汤用于发汗，桂枝汤用于解肌。这里说桂枝汤发汗，并非发汗就是解肌。大概是利用桂枝汤中的芍药，引导桂枝、生姜的辛温之气进入阴分，从而驱除传入的邪气，这就是所谓的“阳因阴用”。而且桂枝、芍药都能走肝经，更可引导太阴的邪气，由少阳传入者，返回少阳而出。此桂枝汤只要见到太阴脉浮即可发汗，不可拘泥于风邪用桂枝、寒邪用麻黄的说法。邪气在太阳、阳明时，还要区分风寒两种病因的来源，等到由阳明传到少阳，已经不可再区分，再传给太阴，难道还能区分风因还是寒因吗？再者，麻黄汤一概辛热，不能进入阴分，即使能辨别是寒因，也不宜使用。加之没有不经由少阳而直接驱入太阳的道理。麻黄汤的力量，只是轻清上升，达于太阳，也不能假借少阳的道路。所以不言麻黄汤，不是遗漏，也不是列举桂枝汤来概括所有情况。知晓这一点，太阴邪气的出路，必然由少阳返回太阳，其他说法都不足以迷惑人。
麻黄汤走向阴分，在营血层面能够进入，因为在太阳之表，要进入三阴的阴分，则不能进入，因为它只有升而没有降。这也是应该知道的。
【纲要】张仲景说：太阴中风，四肢烦疼。脉象阳微阴涩而长的，是快要痊愈的表现。
【目次】方中行说：四肢烦疼，脾主四肢，这也是风邪侵袭末梢疾病的明显验证。
魏荔彤说：脉象见长，则邪气从太阴想要回归复归于少阳是必然的了。脾为脏，位于里，经邪内陷，则症状表现为腹部胀满疼痛、呕吐不能进食等。如果经邪想要外出，则症状表现在四肢末端，而不久就会留在体内陷入可知。于是阳脉微、阴脉涩，邪气已有渐渐透达至营卫之势，兼以弦长，显示少阳的门户开启，生发之气已经发动。再加上四肢之间，蠢蠢欲动的烦疼，出汗发热，其邪气纯粹回归太阳了。邪气不由太阳而去，怎么能自行停止呢？
[General Principle] Zhang Zhongjing said: In a cold damage disease, if the pulse is floating and slow, and the hands and feet are naturally warm, this indicates the pathogen is associated with the Taiyin (Greater Yin) channel. A Taiyin disease should manifest as jaundice; however, if urination is free and unobstructed, jaundice will not develop. By the sixth or seventh day, although there may be sudden irritability and diarrhea occurring more than ten times a day, the diarrhea must stop spontaneously. This is because the Spleen's healthy qi has recovered (Spleen Excess), and the rotting filth within the body is destined to be expelled.
[Commentary] Zhu Gong said: The Foot-Taiyin Spleen meridian is the head of the Three Yin channels. Its vessels distribute to the Stomach and Spleen and connect with the throat. Therefore, when a patient presents with abdominal fullness and a dry throat, and both the Cun (inch) and Chi (cubit) pulses are deep and fine, it is known that the Taiyin channel is affected by disease. Four or five days after contracting cold damage, if the patient presents with abdominal fullness, dry throat, naturally warm hands and feet, or spontaneous diarrhea without thirst, or abdominal fullness with intermittent pain, and both Cun and Chi pulses are deep and fine, this indicates the Foot-Taiyin Spleen channel is affected. In cold damage diseases, hands and feet are usually slightly cold; if they are naturally warm, the disease belongs to Taiyin. Spontaneous diarrhea that does not cease belongs to Taiyin. Abdominal fullness with intermittent pain belongs to Taiyin. Spontaneous diarrhea without thirst indicates internal cold of the zang organs. One should employ warming methods, suitable for using Sini Tang (Four Reversal Decoction) or Lizhong Tang (Regulate the Middle Decoction). If abdominal fullness is accompanied by a floating pulse, Guizhi Tang (Cinnamon Twig Decoction) can be used to induce slight sweating. If there is abdominal pain, use Guizhi Jia Shaoyao Tang (Cinnamon Twig Decoction with Added Peony). For severe cases, use Guizhi Jia Dahuang Tang (Cinnamon Twig Decoction with Added Rhubarb).
Wei Litong said: A floating and slow pulse with warm hands and feet resembles Taiyang Wind Strike, but since the hands and feet cannot become hot, it indicates that the Spleen organ inherently possesses damp-evil, which mixes with the wind-cold transforming into heat evil. Thus, significant heat cannot manifest on the exterior, but profound heat is actually accumulated in the interior. Clarifying that the disease is tied to Taiyin, the body should develop jaundice, similar to jaundice symptoms in Taiyang disease, signifying the accumulation of heat in the interior. If urination is smooth, dampness is drained and heat departs, so jaundice does not occur. This was discussed in the Yangming chapter; its repetition here serves to contrast with the previous context where Taiyang initially entered Yangming. If the Spleen inherently has dampness, it cannot form a Stomach Excess condition. When exterior heat enters, it only results in jaundice. Stomach Excess is originally caused by the depletion of fluids internally, where intense heat creates excess. Since dampness exists, and dampness is also a form of fluid, it does not form Stomach Excess but rather jaundice. By the seventh or eighth day, prolonged heat consumes fluids, thus re-forming Stomach Excess, verified by hard stool. Zhang Zhongjing identified this as Yangming disease, which differs fundamentally from Taiyin disease in origin. This case also begins with initial entry from Taiyang, but the disease ultimately does not enter Yangming. Hence, Zhang Zhongjing points out this as Taiyin Spleen Excess. When wind-cold transforms into heat and transmits inward, specifically because the Spleen inherently has dampness, the heat evil投s into the dampness like smoke into water, all tending toward the Spleen to cause pathology. Thus, jaundice does not occur. The above points align with those in the Yangming chapter. However, at seven or eight days, not only is the stool not hard, but there is sudden irritability and diarrhea more than ten times a day. The initial entry is the same, but the progression diverges. Heat overcoming dampness leads to Stomach Excess and hard stool; dampness overcoming heat, with dampness lingering and heat seeking exit, leads to Spleen Excess and diarrhea. This distinction between Stomach Excess and Spleen Excess hinges on the concepts of dampness and heat. Dampness is a yin evil, stagnant, capable of lingering; heat is a yang evil, swift, demanding exit. Since urination does not fully drain the heat and jaundice does not appear, where does the heat go? It must flow downward with the dampness into the large intestine. Rotting filth previously retained by heat during diarrhea will inevitably be expelled along with it, driven by an uncontrollable force. This Spleen Excess belongs to Taiyin, while Stomach Excess belongs to Yangming; the distinction lies solely in dampness versus heat, creating clearly different syndromes for the two channels. Regarding these two clauses lacking prescriptions: for Yangming Stomach Excess, one should adjust among the four Chengqi Decoctions according to the individual; for Taiyin Spleen Excess with diarrhea, before diarrhea starts, how to drain dampness and dry the earth? After diarrhea starts, how to tonify the middle and benefit the Spleen? Or simultaneously drain dampness and clear heat? These require the physician's judgment. Moreover, if expelling the filth cures the patient, medication might not even be necessary.
Yu Chang said: The Taiyin pulse is naturally slow. Although floating and slow resembles Taiyang Wind Strike, naturally warm hands and feet differ from Taiyang fever, and certainly differ from the cold limbs and reversal cold of Shaoyin and Jueyin. Thus, the disease ties to Taiyin. The inability to develop jaundice aligns with statements in the Yangming chapter. However, in Yangming, hard stool due to Stomach Excess causes symptoms to revert to Yangming; here, foul expulsion due to Spleen Excess keeps symptoms within Taiyin. By the seventh or eighth day, sudden irritability and diarrhea more than ten times a day resemble Shaoyin disease. Yet, once the filth is exhausted, diarrhea stops spontaneously, unlike Shaoyin where irritability worsens and diarrhea has no end. Furthermore, in Shaoyin, if irritability and diarrhea are accompanied by warming hands and feet and the disappearance of a tight pulse, it indicates impending recovery. Failure to distinguish this and mistakenly treating with Sini Tang would increase danger.
[General Principle] Zhang Zhongjing said: In cold damage disease with diarrhea occurring more than ten times a day, if the pulse is unexpectedly excessive and forceful, death ensues.
[Commentary] Yu Tun said: When Spleen qi is deficient and pathogenic qi is abundant, the pulse becomes unexpectedly excessive.
[General Principle] Zhang Zhongjing said: In Taiyin disease, if the pulse is weak and the person continues to have loose stools, if Da Huang (Rhubarb Root and Rhizome) or Shao Yao (Peony Root) were indicated, their dosage should be reduced. This is because the Stomach qi is weak and easily disturbed.
[Commentary] Yu Chang said: This admonition complements the discussion in the Yangming chapter. Yangming warns against non-passing of flatus, hard stool followed by loose stool, and uncertain hardness, fearing injury to Taiyin Spleen qi. Here, weak pulse and loose stools warn against reducing Da Huang and Shao Yao to avoid injuring Yangming Stomach qi.
[General Principle] Zhang Zhongjing said: Chills, a faint pulse, and recurrent diarrhea indicate loss of blood. Treat with Sini Jia Renshen Tang (Four Reversal Decoction plus Ginseng).
[Commentary] Zhu Gong said: Diseases presenting with chills without fever originate from the Yin channels. Originating from Yin requires warming the interior. The pulse will be faint, or deep and fine, indicating suitability for Sini Jia Renshen Tang, Sini Tang, or Lizhong Tang. If there is fever with slight chills, it belongs to Chaihu Guizhi Tang (Bupleurum and Cinnamon Twig Decoction).
Shen Jin'ao notes: Since chills have not ceased, Sini Tang is appropriate. Since the faint pulse indicates lack of blood, adding Renshen (Ginseng Root) is appropriate.
[General Principle] Zhang Zhongjing said: In Taiyin disease, if the pulse is floating, sweating may be induced. Use Guizhi Tang (Cinnamon Twig Decoction).
[Commentary] Zhu Gong said: Questioning ancients regarding Taiyin syndrome appearing on the fourth day with pathology in the chest and diaphragm, curable by emesis. Answer: Incorrect. For Taiyin syndrome with a large pulse, chest fullness, and much phlegm, emesis is applicable. For a large pulse without phlegm symptoms, sweating is sufficient. Generally, treat exterior conditions with sweating, interior conditions with purging, upper conditions with vomiting, and lower conditions with draining. Genti San (Thistle Powder) and Zhizi Chichi Tang (Gardenia and Soybean Decoction) are applied according to symptoms; one should not be bound by the number of days.
Wei Litong said: Pathogens transmit from Taiyang to Yangming, then to Shaoyang, and finally to Taiyin. The method should aim to raise the pathogen back to Shaoyang, allowing it to exit via the half-exterior of Shaoyang to the exterior of Taiyang, combining treatments for Yang channels. In Taiyin disease, if the pulse is not deep and slow but floating, the pathogen entering the Yin channels seeks to depart from Yang and exit outward. Urgent sweating should be induced to allow the pathogen to escape outward, curing the disease. In Taiyang, Mahuang Tang (Ephedra Decoction) induces sweating, while Guizhi Tang releases the muscle layer. Saying Guizhi Tang induces sweating here does not equate sweating with releasing the muscle layer. It utilizes Shaoyao (Peony) in Guizhi Tang to guide the acrid-warm nature of Guizhi (Cinnamon Twig) and Shengjiang (Fresh Ginger) into the Yin aspect to drive out the transmitted pathogen, known as "Yang utilizing Yin." Furthermore, both Guizhi and Shaoyao enter the Liver channel, guiding Taiyin pathogens transmitted from Shaoyang back through Shaoyang to exit. Thus, Guizhi Tang can induce sweating whenever a Taiyin floating pulse is seen, without adhering to the rule that wind uses Guizhi and cold uses Mahuang. When pathogens are in Taiyang and Yangming, one distinguishes wind vs. cold origins. Once transmitting from Yangming to Shaoyang, distinction is impossible; further transmission to Taiyin makes such distinction irrelevant. Additionally, Mahuang Tang is entirely acrid-hot and cannot enter the Yin aspect; even if cold is identified, it is unsuitable. There is no mechanism to drive pathogens directly from Shaoyang to Taiyang without passing through intermediate stages. Mahuang Tang's power rises lightly and clears, reaching only Taiyang, unable to borrow the Shaoyang pathway. Thus, Mahuang Tang is not mentioned, not due to omission, nor to generalize Guizhi Tang. Understanding this, the exit route for Taiyin pathogens must return from Shaoyang to Taiyang; other theories are insufficient to confuse this principle.
Mahuang Tang entering the Yin aspect works in Ying and Blood levels because it is at the Taiyang exterior; entering the Yin aspect of the Three Yin channels fails because it ascends without descending. This too must be understood.
[General Principle] Zhang Zhongjing said: In Taiyin Wind Strike, with painful and uncomfortable limbs, if the pulse is faint externally, choppy internally, yet long, recovery is imminent.
[Commentary] Fang Zhongxing said: Painful and uncomfortable limbs confirm that the Spleen governs the limbs and validates the concept of wind invading the extremities.
Wei Litong said: A long pulse indicates the pathogen is likely returning from Taiyin to Shaoyang. The Spleen is an interior zang organ; if channel pathogens sink inward, symptoms include abdominal fullness, pain, vomiting, and inability to eat. If channel pathogens seek to exit outward, symptoms manifest in the extremities, proving they do not remain sunk inward. Thus, a faint external pulse and choppy internal pulse show the pathogen gradually penetrating to the Ying and Wei levels. Combined with a string-like and long quality, it shows the Shaoyang gate opening and generating qi activating. Coupled with restless pain in the extremities, sweating, and fever, the pathogen purely returns to Taiyang. If the pathogen does not exit via Taiyang, how can it cease spontaneously?