齐，犹一也。刺齐，刺浅刺深，无过不及，有一定之分也。如病在皮中，针入皮中，勿浅勿深，斯
为刺齐。以皮分而推之脉肉筋骨。无太过，无不及，皆为刺齐。承上编刺要之意，而复论刺齐也。
黄帝问曰∶原闻刺浅深之分。
分，去声。帝承上编刺有浅深之意，谓刺浅刺深，各有部分，故愿闻刺浅深之分。
岐伯对曰∶刺骨者无伤筋，刺筋者无伤肉，刺肉者无伤脉，刺脉者无伤皮。
欲知其分，必先知其非分。如刺骨者刺入骨分，无伤其筋；刺筋者刺入筋分，无伤其肉；刺肉者刺
入肉分，无伤其脉。脉有络脉，有经脉。上编脉居肉后，经脉也。此篇脉居肉先，络脉也。刺
脉者，刺入脉分，无伤其皮。此言刺宜深者勿浅，浅则非分矣。
刺皮者无伤肉，刺肉者无伤筋，刺筋者无伤骨。
以上文层次言之，当云刺皮者无伤脉。今不言脉者，以脉不止络脉、复有经脉。络脉居肉前，经脉
居肉后，言肉而脉在其中。故曰刺皮者刺入皮分，无伤其肉；刺肉者刺入肉分，无伤其筋；刺筋
者刺入筋分、无伤其骨。此言刺宜浅勿深，深则非分矣。
帝曰∶余未知其所谓，愿闻其解。
刺宜深者勿浅，宜浅者勿深，是浅深有一定之分。帝欲详明其
说，以昭后世，故曰未知所谓，愿闻其解。
岐伯曰∶刺骨无伤筋者，针至筋而去，不及骨也。刺筋无伤肉者，至肉而去，不及筋也。
刺肉无伤脉者，至脉而去，不及肉也。刺脉无伤皮者，至皮而去，不及脉也。
所云刺骨无伤筋者，言针至筋而去，不及骨分，则伤筋也；所云刺筋无伤肉者，言针至肉而去，
不及筋分，则伤肉也；所云刺肉无伤脉者，言针至脉而去，不及肉分，则伤脉也；所云刺脉无伤皮
者，言针至皮而去，不及脉分，则伤皮也。此解上文其刺宜深，不及则伤之意。
所谓刺皮无伤肉者，病在皮中，针入皮中，无伤肉也；刺肉无
伤筋者，过肉，中筋也；刺筋无伤骨者，过筋，中骨也。
过，平声。中筋、中骨之中，去声。上文所谓刺皮无伤肉者，如病在肉中，则针入皮中，无过分，
而伤肉也；所谓刺肉无伤筋者，病在肉中，针入肉中，如过肉，则中伤其筋也；所谓刺筋无伤
骨者，病在筋中，针入筋中，如过筋，则中伤其骨也。此解上文其刺宜浅，过分则伤之意。
此之谓反也。
通承上文之意，而言刺非其分，浅深不得，此之谓反也。知其反则知其正矣。
Qi (Standard/Measure), means "one" or uniformity. Ci Qi (Standard of Needling) refers to the depth of needling, ensuring neither excess nor deficiency, adhering to a fixed measure. For instance, if the pathology is in the skin layer, the needle should be inserted into the skin layer, neither too shallow nor too deep; this is called Ci Qi. By analyzing the layers of skin, vessels, flesh, sinews, and bones, avoiding both excess and deficiency constitutes Ci Qi. This continues the theme of the previous section on the essentials of needling, further discussing the standard of needling depth.
The Yellow Emperor asked: I wish to hear about the distinction between shallow and deep needling.
"Fen" (Distinction/Part), pronounced with the departing tone. The Emperor, following up on the previous discussion that needling has varying depths, stated that shallow and deep needling each have their specific locations, thus wishing to understand the distinction between shallow and deep needling.
Qibo replied: When needling the bone, do not injure the sinews; when needling the sinews, do not injure the flesh; when needling the flesh, do not injure the vessels; when needling the vessels, do not injure the skin.
To know the correct measure, one must first know what is incorrect. For example, when needling the bone, the needle should enter the bone's region without injuring the sinews above it; when needling the sinews, the needle should enter the sinew's region without injuring the flesh outside it; when needling the flesh, the needle should enter the flesh's region without injuring the vessels within it. Vessels are divided into Luo vessels (Collateral vessels) and Jing vessels (Primary meridians). In the previous section, the vessel mentioned was behind the flesh, referring to the Jing vessels. In this section, the vessel mentioned is in front of the flesh, referring to the Luo vessels. When needling the vessels, the needle should enter the vessel's region without injuring the skin outside it. This passage explains that when deep needling is required, failing to reach the depth is incorrect.
When needling the skin, do not injure the flesh; when needling the flesh, do not injure the sinews; when needling the sinews, do not injure the bone.
Speaking in terms of the hierarchy mentioned above, one might say "when needling the skin, do not injure the vessels." However, vessels are not mentioned here because they include not only Luo vessels but also Jing vessels. Luo vessels are located in front of the flesh, while Jing vessels are located behind the flesh; thus, mentioning the flesh implies the presence of vessels within it. Therefore, it is said that when needling the skin, the needle should enter the skin's region without injuring the flesh below it; when needling the flesh, the needle should enter the flesh's region without injuring the sinews below it; when needling the sinews, the needle should enter the sinew's region without injuring the bone below it. This passage explains that when shallow needling is required, exceeding the depth is incorrect.
The Yellow Emperor said: I do not understand what you mean; I wish to hear your explanation.
When deep needling is required, it should not be shallow; when shallow needling is required, it should not be deep. This indicates that there is a fixed standard for depth. The Emperor wished to clarify this theory to illuminate it for future generations, hence saying he did not understand and wished to hear the explanation.
Qibo said: "Needling the bone without injuring the sinews" means the needle reaches the sinew level and stops, without reaching the bone. "Needling the sinews without injuring the flesh" means the needle reaches the flesh level and stops, without reaching the sinew. "Needling the flesh without injuring the vessels" means the needle reaches the vessel level and stops, without reaching the flesh. "Needling the vessels without injuring the skin" means the needle reaches the skin level and stops, without reaching the vessel.
The phrase "needling the bone without injuring the sinews" means that if the needle stops at the sinew level and does not reach the bone, it fails to treat the bone and thus injures the sinew by missing the target. The phrase "needling the sinews without injuring the flesh" means that if the needle stops at the flesh level and does not reach the sinew, it fails to treat the sinew and thus injures the flesh. The phrase "needling the flesh without injuring the vessels" means that if the needle stops at the vessel level and does not reach the flesh, it fails to treat the flesh and thus injures the vessel. The phrase "needling the vessels without injuring the skin" means that if the needle stops at the skin level and does not reach the vessel, it fails to treat the vessel and thus injures the skin. This explains the meaning of the previous text: when deep needling is required, insufficient depth causes injury.
The phrase "needling the skin without injuring the flesh" means that if the pathology is in the skin, the needle enters the skin without injuring the flesh. "Needling the flesh without injuring the sinews" means that if the needle passes through the flesh, it hits the sinew. "Needling the sinews without injuring the bone" means that if the needle passes through the sinew, it hits the bone.
"Guo" (Exceed/Pass), pronounced with the level tone. "Zhong" (Hit/Strike) in "Zhong Jin" (Hit Sinew) and "Zhong Gu" (Hit Bone), pronounced with the departing tone. Regarding the previous statement "needling the skin without injuring the flesh": if the pathology is in the flesh, and the needle only enters the skin without passing through, it will not injure the flesh. Regarding "needling the flesh without injuring the sinews": if the pathology is in the flesh, and the needle enters the flesh but exceeds it, it will strike and injure the sinew. Regarding "needling the sinews without injuring the bone": if the pathology is in the sinew, and the needle enters the sinew but exceeds it, it will strike and injure the bone. This explains the meaning of the previous text: when shallow needling is required, excessive depth causes injury.
This is called "Fan" (Reversal/Opposite).
Continuing from the previous context, it states that needling not in the correct location, with improper depth, is called "Fan". Knowing what is "Fan" allows one to know what is "Zheng" (Correct/Proper).