夫用针者。先明其孔穴。补虚泻实。送坚付濡。以急随缓荣卫常行。勿失其理故为针者。勿离乎心口。如衔索
目。欲内视消息气血不得妄行。凡针入一分。则知天地之气。针入二分。则知呼吸出入。上下水火之气。针入三分。
则知四时五行。五脏顺逆之气。凡针皮毛腠理者。勿伤肌肉。针肌肉者。勿伤筋脉。针筋脉者。勿伤骨髓。针骨髓
者。勿伤诸经络。若误伤之。魂魄神志知气失乱。反误人也。学人慎之。（千金）
大寒无刺。（素问云天寒无刺天温无疑）月生无泻。月满无补。新内无刺。已刺无内。大怒无刺。已刺无怒。
大劳无刺。已刺无劳。大醉无刺。已刺无醉。大饱无刺。已刺无饱。大饥无刺。已刺无饥。大渴无刺。已刺无渴。
月郭空无治。
凡乘车来者。须令卧以休息。如食顷。乃可刺之。步行来者。令坐以休息。如行十里顷。乃刺之。若大惊大恐
者必俟定其气。乃刺之。（千金）
答曰。不如是之相拘也。盖肌肉有浅深。病去有迟速。若肌肉浓实处。则可深若浅薄处。则宜浅。病去则速出
针。病滞则久留针。为可耳。（素问针刺）
神应经云。取穴既正。左手大指掐其穴。右手置针于穴上。令患人咳嗽一声。随咳内针至分寸。候数穴针毕停
少时。用右手大指及食指持针细细摇动。进退搓捻。其针如手颤之状。谓之催气。约行五六次。觉针下气紧却用泻
法。如针左边用右手大指食指持针。以大指向前。食指向后。以针头轻提往左转。如有数针。俱根据此法。俱转毕。
仍用右手大指食指持针。却用食指连搓三下。（谓之飞）仍轻轻提往左转。略退针半许。（谓之三飞）根据此法行至五
六次。觉针下沉紧。是气至极矣。再轻轻提往左转。一二次。欲出针时。令病患咳嗽一声。随咳出针。此之谓泻法
也。（大成）
Those who use needles must first clarify the locations of acupoints. By tonifying deficiency and reducing excess, and by harmonizing rigidity and flaccidity, Ying and Wei Qi (Nutritive and Defensive Qi) should circulate normally without violating their principles. Therefore, practitioners must maintain mental focus and manual dexterity, being as cautious as if holding a rope in their mouths. They must be able to visualize internally the flow of Qi and Blood, preventing erratic movement. When the needle is inserted one fen deep, one perceives the Qi of Heaven and Earth; when inserted two fen deep, one perceives the inhalation and exhalation of breath, as well as the Qi of Water and Fire above and below; when inserted three fen deep, one perceives the Qi of the Four Seasons, Five Elements, and the smooth or adverse states of the Zang organs. When needling the skin, hair follicles, and interstices, do not damage the muscles; when needling the muscles, do not damage the tendons and vessels; when needling the tendons and vessels, do not damage the bone marrow; when needling the bone marrow, do not damage the collaterals. If these tissues are mistakenly damaged, it will cause chaos in the Hun and Po spirits, Shen consciousness, and Qi mechanism, thereby harming the patient. Students must exercise caution. (From *Qianjin Fang*)
Do not needle during extreme cold. (*Su Wen* states: Do not needle when it is cold; do not hesitate when it is warm.) Do not apply reducing methods during the waxing moon; do not apply tonifying methods during the full moon. Do not needle immediately after sexual intercourse; avoid intercourse after needling. Do not needle during extreme anger; avoid anger after needling. Do not needle during extreme fatigue; avoid exertion after needling. Do not needle when extremely drunk; avoid drunkenness after needling. Do not needle when overly full; avoid overeating after needling. Do not needle when extremely hungry; avoid starvation after needling. Do not needle when extremely thirsty; avoid extreme thirst after needling. Treatment is contraindicated when the moon is dark and empty.
For patients arriving by carriage, allow them to lie down and rest for about the time it takes to eat a meal before needling. For patients arriving on foot, allow them to sit and rest for about the time it takes to walk ten li before needling. For patients suffering from great fright or terror, wait until their Qi has stabilized before needling. (From *Qianjin Fang*)
The response is: It is not so rigidly constrained. This is because muscles vary in depth, and the resolution of disease varies in speed. In areas with thick muscles, needling can be deeper; in areas with thin muscles, it should be shallow. If the pathogen is easily expelled, remove the needle quickly; if the pathogen lingers, retain the needle for a longer duration. This is appropriate. (From *Su Wen: Needling*)
*Shen Ying Jing* states: Once the acupoint is correctly selected, press the point with the thumb of the left hand, and place the needle on the point with the right hand. Ask the patient to cough once, and insert the needle to the specified depth following the cough. After all designated points are needled, pause briefly. Hold the needle with the thumb and index finger of the right hand, gently shaking, advancing, retreating, twisting, and rolling it, making the needle tremble like a shaking hand. This is called "Cui Qi" (Urging Qi). Perform this about five or six times. When tightness under the needle is felt, then apply the reducing method. For example, when needling the left side, hold the needle with the thumb and index finger of the right hand; push the thumb forward and pull the index finger backward, lightly lifting the needle head and turning it to the left. If multiple points are needled, follow this method for all. After all rotations are complete, still hold the needle with the thumb and index finger of the right hand, and rub it three times continuously with the index finger (this is called "Fei"). Still lightly lift and turn to the left, withdrawing the needle slightly (this is called "San Fei"). Following this method for five or six times, if a heavy and tight sensation is felt under the needle, it indicates that Qi has reached its peak. Lightly lift and turn to the left one or two more times. To withdraw the needle, ask the patient to cough once, and withdraw the needle following the cough. This is called the reducing method. (From *Zhen Jiu Da Cheng*)