补泻者。言呼吸出内以为其法。补之时。从卫取气也。取者。言其有也。素问曰。必先
扪而
循之。切而散之。推而按之。弹而弩之。爪而下之。通而取之。外引其门。以闭其神。呼尽
内针。静以久留。以气至为故。如待贵宾。不知日暮。其气以至。适而自获。候吸引针。气
不得出。各在其处。推阖其门。令神气存。大气留止。故命曰补。是取其气而不令气大出
也。当泻之时
从荣置其气。而不用也。故素问曰。吸则内针。无令气忤。静以久留。无令邪布。吸则转
针。以得气为故。候呼引针。呼尽乃去。大气皆出。故命曰泻。泻者。是置其气而不用也。
若阳气不足。而阴气血有余者。当先补阳而后泻阴。阴血不足而阳气有余者。当先补阴而后
泻阳。以此阴阳调和。荣卫自然通行。此为针之要也。
大言阴与阳。小言夫与妇。阴日阴时则当刺阴干。阳日阳时则当刺阳干。故阴阳者气血
也。
阴日血先气后。阳日气先血后。经云。荣行脉中。卫行脉外。然阴日虽遇阳时。刺阴干者何
也。盖阴日血先行引气。后随血入脉中而行。此为妇有气。夫往从之者。故阴干是也。阳日
虽遇阴时。刺阳干者何也。盖阳日气先行引血。后随气流注在脉外而行。此为夫有气。妇往
从之者。故阳干是也。如斯之论。此之谓也。
补法和泻法，是指通过呼吸的进出作为操作法则。施行补法时，是从卫分（行于脉外、具有护卫作用的阳气）中获取正气。所谓“取”，意思是引导其存在的气机。《素问》说：必须先用手指抚摸并顺着经络推循，接着切按以散开郁结，再推动并按压穴位，弹击穴位使经气激发，用指甲向下按压定位，疏通经络后取穴进针。向外牵引皮肤门户，以封闭神气不外泄。在患者呼气结束时进针，安静地长时间留针，以得气为度。就像等待尊贵的客人一样，不知时间流逝。当经气到来时，恰到好处地获得疗效。候患者吸气时拔针，使气不致随针外出，气机各归其位。推合针孔，使神气留存，大气（正气）停留止息，所以称为补。这是为了摄取正气而不令正气大量耗散。
施行泻法时，是从营分（行于脉中、具有营养作用的血气）中安置气机而不予固守。所以《素问》说：在患者吸气时进针，不让气机逆乱；安静地长时间留针，不让邪气扩散；吸气时转动针具，以得气为度。候患者呼气时拔针，呼气结束时完全拔出，大气（邪气）全部排出，所以称为泻。泻法，就是安置气机而使其不被固守。
如果阳气不足，而阴血有余，应当先补阳而后泻阴。如果阴血不足，而阳气有余，应当先补阴而后泻阳。以此调和阴阳，营卫自然通行，这是针刺的要领。
大的道理讲阴阳，小的道理讲夫妇配合。阴日或阴时，应当刺阴干（天干中的甲、丙、戊、庚、壬属阳，乙、丁、己、辛、癸属阴，此处指代阴经或阴气主导的时间/部位，原文语境下通常对应阴经或特定干支组合，结合下文“刺阴干”理解为针对阴的属性）。阳日或阳时，应当刺阳干。所以阴阳指的是气血。阴日血先动而气后随，阳日气先动而血后随。经文说：营气行于脉中，卫气行于脉外。然而阴日虽然遇到阳时，为什么要刺阴干呢？这是因为阴日血先行，引动气随后进入脉中运行。这好比妇人（阴/血）有气，丈夫（阳/气）前往跟随它，所以称为刺阴干。阳日虽然遇到阴时，为什么要刺阳干呢？这是因为阳日气先行，引动血随后流注在脉外运行。这好比丈夫（阳/气）有气，妇人（阴/血）前往跟随它，所以称为刺阳干。像这样的论述，说的就是这个道理。
Bu (Tonification) and Xie (Evacuation) refer to the method of utilizing respiration for insertion and withdrawal. During tonification, Qi is extracted from the Wei (Defensive Qi, yang qi circulating outside the vessels). "Extraction" implies guiding the existing Qi. The *Su Wen* states: One must first palpate and follow the meridians, press and disperse, push and press, flick and stretch, mark with fingernails, unblock and select the point, draw outward at the aperture to close the Shen (Spirit), and retain it. Insert the needle when exhalation ends, leave it quietly for a long time until Deqi (arrival of Qi) is achieved. Wait as if expecting a distinguished guest, unaware of the passing day. When Qi arrives, obtain the desired effect appropriately. Withdraw the needle during inhalation so that Qi does not escape, each remaining in its place. Push and close the aperture to let the Shen and Qi remain, allowing the Great Qi (Zheng Qi, healthy Qi) to stay and stop. Hence it is called Tonification. This is to take the Qi without letting it escape excessively.
During evacuation, Qi is placed within the Ying (Nutritive Qi, blood and Qi circulating inside the vessels) and not retained. Thus, the *Su Wen* states: Insert the needle during inhalation, do not let the Qi rebel; leave it quietly for a long time, do not let the pathogenic factors spread; rotate the needle during inhalation until Deqi is achieved. Withdraw the needle during exhalation, removing it completely when exhalation ends, so that the Great Qi (pathogenic Qi) all exits. Hence it is called Evacuation. Evacuation means placing the Qi and not retaining it.
If Yang Qi is insufficient while Yin Blood is excessive, one should first tonify Yang and then evacuate Yin. If Yin Blood is insufficient while Yang Qi is excessive, one should first tonify Yin and then evacuate Yang. By this means, Yin and Yang are harmonized, and Ying and Wei circulate naturally. This is the essence of acupuncture.
In grand terms, we speak of Yin and Yang; in minute terms, we speak of Husband and Wife. On Yin days or during Yin hours, one should puncture the Yin Heavenly Stems (referring to Yin meridians or Yin-dominant points). On Yang days or during Yang hours, one should puncture the Yang Heavenly Stems. Therefore, Yin and Yang correspond to Qi and Blood. On Yin days, Blood moves first and Qi follows; on Yang days, Qi moves first and Blood follows. The classics state: Ying Qi circulates within the vessels, while Wei Qi circulates outside. However, why on a Yin day, even if encountering a Yang hour, should one puncture the Yin stems? It is because on a Yin day, Blood moves first, leading Qi to enter the vessels and circulate subsequently. This is like the Wife (Yin/Blood) possessing Qi, and the Husband (Yang/Qi) following her; thus, it is called puncturing the Yin stems. On a Yang day, even if encountering a Yin hour, why should one puncture the Yang stems? It is because on a Yang day, Qi moves first, leading Blood to flow and circulate outside the vessels subsequently. This is like the Husband (Yang/Qi) possessing Qi, and the Wife (Yin/Blood) following him; thus, it is called puncturing the Yang stems. Such discussions are what is meant by this principle.