〔《灵》〕凡针之要，官针最妙。九针之宜，各有所为，长短大小，各有所施也。不得其用，病弗能移。疾
浅针深，内伤良肉，皮肤为痈。病深针浅，病气不泻，反为大脓。病小针大，气泻太甚，疾必为害。病大针小，
气不泄泻，亦复为败。失针之宜，大者泻，小者不移，已言其过，请言其所施。（官针篇）
〔《灵》〕一曰 针，长一寸六分。头大末锐，去泻阳气。（九针十二原， 锄街切。洁古云∶平半寸，
长一寸六分，其头大末锐，主热在头分宜此。）
〔《甲》〕一者天，天者阳也，五脏之应天者肺也，肺者五脏六腑之盖也，皮者肺之合也，人之阳也，故为
治针。 针者，取法于巾针，去末半寸卒锐之，长一寸六分，大其头，锐其末，令无得深入而阳气出，主热
在头身者。故曰∶病在皮肤无常处者，取之 针于病所。肤白勿取。
*Ling Shu* states: In all acupuncture, the key lies in the proper use of the Official Needles. The suitability of the Nine Needles varies, each having its specific function; their lengths and sizes have distinct applications. If their usage is not mastered, diseases cannot be cured. If the disease is superficial but the needle insertion is too deep, it will damage healthy flesh internally, leading to carbuncles on the skin. If the disease is deep but the needle insertion is too shallow, the pathogenic qi will not be discharged, potentially resulting in large abscesses. If the pathology is minor but the needle is too large, excessive discharge of qi will inevitably cause harm. If the pathology is major but the needle is too small, the qi will not be discharged, also leading to treatment failure. Having missed the appropriateness of needling, severe conditions may be drained (by larger needles), while mild conditions remain unaffected (by smaller needles). The errors have been mentioned above; now let us discuss their specific applications. (From *Ling Shu*, Chapter "Guan Zhen")
*Ling Shu* states: The first is the Chan Needle (Chanzhen), one cun and six fen in length. It has a broad head and a sharp tip, used to drain excess Yang heat. (From *Ling Shu*, Chapter "Jiu Zhen Er Shi Er Yuan"; 'Chu' is pronounced as 'Jie'. Jiegu stated: The flat head is half a cun, total length one cun and six fen; with a broad head and sharp tip, it primarily treats heat in the head region.)
*Zhen Jiu Jia Yi Jing* states: One corresponds to Heaven; Heaven belongs to Yang. Among the Five Viscera, the Lung corresponds to Heaven. The Lung is the canopy covering the five viscera and six bowels. The skin is the exterior correspondence of the Lung and represents the Yang of the human body; therefore, it is called the needle for treating the skin. The Chan Needle takes its form from the pin used in headwear. By removing half a cun from the tip to make it abruptly sharp, it measures one cun and six fen in length. Its head is broadened and its tip sharpened, ensuring it does not penetrate deeply, thereby allowing Yang Qi to exit. It primarily treats heat in the head and body. Thus it is said: For diseases located in the skin with no fixed position, use the Chan Needle at the affected site. Do not use it if the skin color is pale.