凡治病服药，必知时禁、经禁、病禁、药禁。夫时禁者，必本四时升降之理，汗、下、吐、利之宜。大法春宜吐，
象万物之发生，耕
耨科斫，使阳气之郁者易达也。夏宜汗，象万物之浮而有余也。秋宜下，象万物之收成，推
陈致新，而使阳气易收也。冬周密，象万物之闭藏，使阳气不动也。经云∶夫四时阴阳者，
与万物浮沉于生长之门，逆其根，伐其本，坏其真矣。又云∶用温远温，用热远热，用凉远
凉，用寒远寒，无翼其胜也。故冬不用白虎，夏不用青龙，春夏不服桂枝，秋冬不服麻黄，
不失气宜。如春夏而下，秋冬而汗，是失天信，伐天和也。有病则从权，过则更之。
经禁者，足太阳膀胱经为诸阳之首，行于背，表之表，风寒所伤则宜汗，传入本则宜利
小便；若下之太早，必变证百出，此一禁也。足阳明胃经，行身之前，主腹满胀，大便难，
宜下之，盖阳明化燥火，津液不能停，禁发汗、利小便，为重损津液，此二禁也。足少阳胆
经，行身之侧，在太阳、阳明之间，病则往来寒热，口苦胸胁痛，只宜和解；且胆者、无
出无入，又主发生之气，下则犯太阳，汗则犯阳明，利小便则使生发之气反陷入阴中，此三
禁也。三阴非胃实不当下，为三阴无传，本须胃实得下也。分经用药，有所据焉。
病禁者，如阳气不足，阴气有余之病，则凡饮食及药，忌助阴泻阳。诸淡食及淡味之药
，泻升发以助收敛也；诸苦药皆沉，泻阳气之散浮；诸姜、附、官桂辛热之药，及湿面、酒
、大料物之类，助火而泻元气；生冷、硬物损阳气，皆所当禁也。如阴火欲衰而退，以三焦
元气未盛，必口淡淡，如咸物亦所当禁。
药禁者，如胃气不行，内亡津液而干涸，求汤饮以自救，非渴也，乃口干也，非温胜也
，乃血病也。当以辛酸益之，而淡渗五苓之类，则所当禁也。汗多禁利小便，小便多禁发汗
。咽痛禁发汗利小便，若大便快利，不得更利。大便秘涩，以当归、桃仁、麻子仁、郁李仁
、皂角仁，和血润肠，如燥药则所当禁者。吐多不得复吐；如吐而大便虚辄者，此土气壅滞
，以姜、橘之属宣之；吐而大便不通，则利大便，上药则所当禁也。诸病恶疮，及小儿 后
，大便实者，亦当下之，而姜、橘之类，则所当禁也。又如脉弦而服平胃散，脉缓而服黄
建中汤，乃实实虚虚，皆所当禁也。人禀天之湿化而生胃也，胃之与湿，其名虽二，其实一
也。湿能滋养于胃，胃湿有余，亦当泻湿之太过也。胃之不足，惟湿物能滋养。仲景云∶胃
胜思汤饼，而胃虚食汤饼者，往往增剧，湿能助火，火旺郁而不通主大热。初病火旺不可食
，以助火也。察其时，辨其经，审其病，而后用药，四者不失其宜，则善矣。
In treating diseases and administering medicines, one must understand the contraindications of seasons (Shi Jin), meridians (Jing Jin), conditions (Bing Jin), and drugs (Yao Jin). The contraindication of seasons must be based on the principles of the ascending and descending of Qi in the four seasons, and the appropriateness of sweating (Han), purging (Xia), vomiting (Tu), and promoting urination (Li). The general rule is: In spring, vomiting is appropriate, symbolizing the generation of all things, like plowing, weeding, and pruning, to allow stagnant Yang Qi to easily reach the surface. In summer, sweating is appropriate, symbolizing the floating and surplus state of all things. In autumn, purging is appropriate, symbolizing the harvest of all things, pushing out the old and bringing in the new, so that Yang Qi can easily converge. In winter, one should be meticulous and hidden, symbolizing the closure and storage of all things, keeping Yang Qi from moving recklessly. The Classic says: The Yin and Yang of the four seasons float and sink with all things in the gate of growth; violating this root destroys the foundation and ruins the true Qi. It also says: When using warm remedies, stay away from warm seasons; when using hot remedies, stay away from hot seasons; when using cool remedies, stay away from cool seasons; when using cold remedies, stay away from cold seasons. Do not assist the prevailing excess. Therefore, do not use Baihu Tang (White Tiger Decoction) in winter, Qinglong Tang (Azure Dragon Decoction) in summer, Guizhi Tang (Cinnamon Twig Decoction) in spring and summer, and Mahuang Tang (Ephedra Decoction) in autumn and winter. This does not violate the appropriateness of Qi seasons. If one uses purging in spring and summer, or sweating in autumn and winter, it is losing the trust of Heaven and destroying the Harmony of Heaven. However, if there is an existing disease, one may act according to circumstances (Quan); once resolved, adjustments must be made.
The contraindication of meridians: The Foot-Taiyang Bladder Meridian is the head of all Yang meridians, running along the back, the exterior of the exterior. When injured by Wind-Cold, sweating is appropriate; if the pathogen transmits into the interior of this meridian, promoting urination is appropriate. If purging is used too early, hundreds of transformed syndromes will emerge; this is the first contraindication. The Foot-Yangming Stomach Meridian runs along the front of the body, governing abdominal fullness and distension, and difficult defecation, for which purging is appropriate. Since Yangming transforms into Dryness-Fire, and Body Fluids cannot remain, sweating and promoting urination are prohibited to avoid further damaging Body Fluids; this is the second contraindication. The Foot-Shaoyang Gallbladder Meridian runs along the side of the body, between Taiyang and Yangming. Disease presents as alternating chills and fever, bitter taste in the mouth, and chest/hypochondriac pain, requiring only Harmonization (He Jie). Moreover, the Gallbladder has no exit or entry, and governs the generating Qi. Purging violates Taiyang, sweating violates Yangming, and promoting urination causes the generating Qi to sink into the Yin; this is the third contraindication. The Three Yin meridians should not be purged unless there is a Full condition of the Stomach, because the Three Yin have no transmission, and originally purging is only indicated when the Stomach is Full. Prescribing according to meridians has its basis.
The contraindication of conditions: For diseases where Yang Qi is insufficient and Yin Qi is excessive, all diet and medicine should avoid assisting Yin and draining Yang. All bland foods and bland-flavored drugs drain the ascending/generating Qi and assist convergence. All bitter drugs are sinking and drain the scattering/floating Yang Qi. All pungent-hot drugs like Sheng Jiang (Zingiberis Rhizoma Freshum), Fu Zi (Aconiti Lateralis Radix Praeparata), and Guan Gui (Cinnamomi Cortex), as well as damp noodles, wine, and strong spices, assist Fire and drain Yuan Qi. Cold/raw and hard foods damage Yang Qi and are all prohibited. If Yin-Fire desires to decline but Sanjiao Yuan Qi is not yet vigorous, leading to a bland taste in the mouth, even salty foods should be prohibited.
The contraindication of drugs: If Stomach Qi does not move, internal Body Fluids are lost and dried up, seeking soup/drink to save oneself is not thirst, but dry mouth; it is not Warmth overcoming Cold, but a Blood disorder. One should benefit with Pungent and Sour substances, while bland-draining formulas like Wuling San (Five-Ingredient Powder with Poria) are prohibited. Excessive sweating prohibits promoting urination; excessive urination prohibits sweating. Sore throat prohibits sweating and promoting urination. If defecation is rapid and free, do not use laxatives again. For constipation and涩 (obstruction), use Dang Gui (Angelicae Sinensis Radix), Tao Ren (Persicae Semen), Maziren (Bambusae Semen), Yuliren (Pruni Semen), and Zaojiaoren (Gleditsiae Fructus Spina) to harmonize Blood and moisten Intestines; drying drugs are prohibited. Excessive vomiting prohibits re-vomiting. If vomiting occurs with loose stools, this is Earth Qi stagnation, treated with Sheng Jiang (Zingiberis Rhizoma Freshum) and Ju Pi (Citri Reticulatae Pericarpium) to disperse; if vomiting occurs with constipation, promote defecation, while the aforementioned dispersing/vomiting methods are prohibited. For various diseases with malignant sores, and after pediatric exanthems, if stools are solid, purging is appropriate, while Sheng Jiang and Ju Pi are prohibited. Furthermore, taking Pingwei San (Peaceful Stomach Powder) for a Xian (Wiry) pulse, or Huangqi Jianzhong Tang (Astragalus Decoction to Establish the Middle) for a Huan (Slow/Relaxed) pulse, constitutes "reinforcing the Excess and depleting the Deficiency," which is prohibited. Humans are born from Heaven's Dampness transforming into the Stomach. Stomach and Dampness, though named differently, are essentially one. Dampness nourishes the Stomach; if Stomach-Dampness is excessive, one must purge the excess Dampness. If Stomach Qi is deficient, only damp-nourishing foods can sustain it. Zhang Zhongjing said: When Stomach Qi is excessive, one craves Tangbing (soup cakes); those with Stomach deficiency eating Tangbing often worsen their condition, because Dampness assists Fire, and Fire flourishing with stagnation leads to Great Heat. In initial Fire flourishing, one should not eat such foods to avoid assisting Fire. Observe the season, differentiate the meridian, examine the condition, then prescribe medication. If these four aspects do not miss their appropriateness, then it is excellent.