（《灵枢·终始篇》）
阴盛而阳虚，先补其阳，后泻其阴而和之；阴虚而阳盛，先补其阴，后泻其阳而和之。（此以脉口人迎言阴阳也。脉
口盛者，阴经盛而阳经虚也，当先补其阳、后泻其阴而和之。人迎盛者，阳经盛而阴经虚也，当先补其阴、后泻其阳而
和之。何也？以治病者皆宜先顾正气，后治邪气。盖攻实无难，伐虚当畏，于此节之义可见。用针用药，其道皆然。）三
脉动于足大趾之间，必审其实虚。虚而泻之，是谓重虚，重虚病益甚。（三脉动者，阳明起于大趾次趾之间，自厉兑以至
冲阳皆是也；厥阴起于大趾之间，自大敦以至太冲皆是也；少阴起于足心，自涌泉以上太溪皆是也。三者皆在大趾之后，
故曰动于足大趾之间也。虚而泻之，故病益甚。）凡刺此者，以指按之，脉动而实且疾者疾泻之，虚而徐者则补之，反此
者病益甚。（泻虚补实，是为反也。）其动也，阳明在上，厥阴在中，少阴在下。（阳明行足跗之上，厥阴行足跗之内而在
二经之中，少阴行足跗之下也。）
补须一方实，深取之，稀按其 ，以极出其邪气；（同前《终始篇》。补当作刺。刺法虽多，其要惟二，则补泻而已。
一者因其方实，故当深取之，勿按其 ，欲以出其邪气，此泻法也。 ，委、伟二音，针瘢也。）一方虚，浅刺之，以养
其脉，疾按其 ，无使邪气得入。（一者因其方虚，故当浅刺之以养其血脉，疾按其穴以拒其邪气，此补法也。）邪气来
也紧而疾，谷气来也徐而和。（邪气，病气也。谷气，元气也，即胃气也。此虽以针下之气为言，然脉气之至亦如此。）
脉实者，深刺之，以泄其气；脉虚者，浅刺之，使精气无得出，以养其脉，独出其邪气。（诸篇皆言虚实，而未详虚实之
辨；此言脉实则实，脉虚则虚，实则深刺之以泄其气，虚则浅刺之无伤精气，以养其脉而独出其邪气，庶补泻知其要矣。）
(From *Ling Shu: Zhong Shi Pian*)
When Yin is excessive and Yang is deficient, one should first tonify Yang, then drain Yin to harmonize; when Yin is deficient and Yang is excessive, one should first tonify Yin, then drain Yang to harmonize. (The Yin and Yang mentioned here refer to the pulse at Maikou [Cunkou, radial artery] and Renying [Jiajie, carotid artery]. An excess pulse at Maikou indicates excess in the Yin meridians and deficiency in the Yang meridians; thus, one should first tonify Yang and then drain Yin to harmonize. An excess pulse at Renying indicates excess in the Yang meridians and deficiency in the Yin meridians; thus, one should first tonify Yin and then drain Yang to harmonize. Why? Because in treating disease, it is appropriate to first protect the Zheng Qi [Upright Qi], and subsequently treat the Xie Qi [Pathogenic Qi]. Attacking excess is not difficult, but attacking deficiency requires caution. The meaning of this section illustrates this principle. Whether using acupuncture or herbal medicine, the approach is the same.)
The three meridians pulsating between the big toe must be carefully examined for excess or deficiency. If they are deficient but drained, this is called "double deficiency," which will cause the disease to worsen. (The three pulsating meridians are: the Yangming Meridian of Foot-Yangming Stomach starts between the second toe, from Lidui [ST45] to Chongyang [ST42]; the Jueyin Meridian of Foot-Jueyin Liver starts between the big toe, from Dadun [LR14] to Taichong [LR3]; the Shaoyin Meridian of Foot-Shaoyin Kidney starts at the sole of the foot, from Yongquan [KI1] upwards to Taixi [KI3]. All three are located behind the big toe, hence described as pulsating between the big toe. Because they are deficient yet drained, the disease worsens.)
When needling these areas, press with fingers to palpate. If the pulse is firm and rapid, drain it quickly; if the pulse is weak and slow, tonify it. Doing the opposite will worsen the disease. (Draining deficiency and tonifying excess constitutes a contraindicated reversal.)
Their pulsation locations are: Yangming is superior, Jueyin is intermediate, and Shaoyin is inferior. (Yangming runs on the dorsum of the foot; Jueyin runs on the medial aspect of the dorsum, between the other two meridians; Shaoyin runs on the inferior aspect of the dorsum.)
For tonification [Note: Text suggests 'Bu' should be read as 'Ci' (needling) in context of method description, but follows standard tonification protocol]: In cases of deficiency, needle shallowly to nourish the Mai [Vessels/Meridians], and press the acupoint quickly to prevent pathogenic Qi from entering. (Because it is deficient, shallow needling nourishes the blood vessels; quick pressure at the acupoint repels pathogenic Qi. This is the tonification method.)
When Xie Qi [Pathogenic Qi] arrives, it feels tight and rapid; when Gu Qi [Grain Qi/Stomach Qi/Upright Qi] arrives, it feels slow and harmonious. (Xie Qi refers to pathogenic Qi. Gu Qi refers to Yuan Qi [Original Qi], i.e., Wei Qi [Stomach Qi]. Although this describes the sensation under the needle, the arrival of Mai Qi [Pulse Qi] is similar.)
If the pulse is excess, needle deeply to drain the Qi; if the pulse is deficiency, needle shallowly so that Jing Qi [Essence Qi] does not escape, thereby nourishing the Mai and exclusively expelling the Xie Qi. (Various chapters discuss excess and deficiency but do not detail their differentiation. Here, it states that an excess pulse indicates an excess syndrome, and a deficiency pulse indicates a deficiency syndrome. Excess syndromes require deep needling to drain Qi; deficiency syndromes require shallow needling to avoid damaging Essence Qi, thus nourishing the Mai and exclusively expelling Pathogenic Qi. This clarifies the essentials of tonification and draining.)