行针分寸中指传，屈指中节两纹尖，男左女右童稚一，长短肥瘦审经权。
【注】行针取分寸法，以同身寸法为准，男左手，女右手，以中指第二节，屈指两纹
尖，相去为一寸，童稚亦如之。虽人身有长短，体有肥瘦，入针之分数不一，而身形之
长者，其指节亦长，身形短者，其指节亦短，但随其长短，以取分寸，则自准矣。肥人肌
肉肥浓，血气充满，宜刺三分半；瘦人肌肉瘦薄，血气未盛，宜刺二分。然虽如此，犹
当有经有权，不可执一而论。如遇不肥不瘦之人，只在二三分之间，酌量取之可也。
\r中指定同身寸图\p06-d43a10.bmp\r
男左女右手中指第二节、屈指两纹尖相去为一寸。取稻秆心量，或薄篾量，皆易折而不伸缩
为准，用绳则伸缩不便，故多不准。
出井流荥注为俞，行经入合脏俞原。春宜针荥夏针俞，秋宜针合冬井间。脏病针俞
腑病合，脏腑有病皆针原。凡诸井穴肌肉浅，不宜深针自古传。
【注】井、荥、俞、经、合、原，十二经穴名也。手足阳经有原穴，手足阴经无原穴，阴之俞穴，即阴之
原穴也。所出为井，井者如水之出也；所流为荥，荥者如水之流也；所注为俞，俞者如水之注也；所行为经，
经者如水之行也；所入为合，合者如水之会也；原者如水之源也。夫春针荥者，取络脉在分肉间，刺之浅者也；
夏针俞者，取孙络在肌肉皮肤之上也；秋针合者，亦取络脉在分肉间，故如春时之所刺；冬针井者，取络脉孙络
之下，比他时所刺，则深而留之，以冬气入脏故也。经原之原，手足阴阳之经，诸病皆宜刺之，但所刺有深有
浅，不能枚举。此四时针刺之大旨，自古相传者也。
行针时的分寸测量，以中指同身寸法为准则。具体方法是：弯曲中指中节，以两横纹尖端之间的距离作为一寸的标准。男性取左手，女性取右手，儿童则不分男女均适用此法。对于身体长短、体型肥瘦不同者，需根据经脉情况进行权衡调整。
【注】行针时确定分寸的方法，以同身寸法为准。男性用左手，女性用右手，将中指第二节弯曲，两指节横纹尖端之间的距离为一寸，儿童也采用同样的方法。虽然人的身材有高矮之分，体质有肥瘦之别，进针的深度各不相同，但身材高大的人，其指节也较长；身材矮小的人，其指节也较短。只要随着其指节的长短来取分寸，自然就是准确的。肌肉丰厚的人，气血充盛，适宜刺入三分半；肌肉消瘦的人，气血未盛，适宜刺入二分。然而虽然如此，仍然应当懂得变通（经权之道），不可拘泥于一种说法。如果遇到不胖不瘦的人，只在二三分之间，酌情选取即可。
井穴如水源初出，荥穴如水流细小，俞穴如水流灌注，经穴如水流运行，合穴如水流汇合，原穴如水源之本。春季适宜针刺荥穴，夏季适宜针刺俞穴，秋季适宜针刺合穴，冬季适宜针刺井穴和间使穴（此处“间”可能指代特定穴位或泛指，结合上下文及常规理论，冬刺井，此处原文作“冬井间”，通常理解为冬刺井穴，间使为心包经穴，或指冬季针刺宜浅或深之变通，依原文直译）。脏病针刺俞穴，腑病针刺合穴，脏腑有病皆可针刺原穴。凡是诸井穴所在部位肌肉较浅，自古以来就认为不宜深刺。
【注】井、荥、俞、经、合、原，是十二经脉的穴位名称。手足阳经有原穴，手足阴经没有单独的原穴，阴经的俞穴即为其原穴。所出之处为井，井如同水的源头；所流之处为荥，荥如同水的细流；所注之处为俞，俞如同水的灌注；所行之处为经，经如同水的长流；所入之处为合，合如同水的汇合；原如同水的本源。所谓春季针刺荥穴，是因为络脉位于分肉之间，针刺较浅；夏季针刺俞穴，是因为孙络位于肌肉皮肤之上；秋季针刺合穴，也是取络脉在分肉之间，所以与春季针刺情况相似；冬季针刺井穴，是取络脉孙络之下，比其他季节针刺更深且留针时间更长，因为冬季寒气入脏的缘故。经穴和原穴，无论手足阴阳各经，各种疾病都适宜针刺，只是针刺有深有浅，无法一一列举。这是四季针刺的大致原则，自古相传。
The measurement of needle insertion depth is transmitted through the middle finger. By bending the middle joint of the middle finger, the distance between the tips of the two transverse creases constitutes one Cun (Chinese inch). For males, use the left hand; for females, use the right hand; for children, this method applies regardless of gender. One must assess the meridians according to the individual's height and body constitution (fat or thin).
[Note] The method for determining needle insertion depth is based on the *Tongshen Cun* (Body-Breadth Inch) system. Males use the left hand, females use the right hand. By flexing the second segment of the middle finger, the distance between the tips of the two creases is defined as one Cun, which also applies to children. Although people vary in stature and body build, leading to different insertion depths, those with taller frames have longer finger segments, while those with shorter frames have shorter segments. By adjusting the measurement according to the length of their finger segments, the accuracy will naturally be achieved. Individuals with thick muscles and abundant Qi and Blood should receive needles inserted to a depth of 3.5 Fen (one-tenth of a Cun); individuals with thin muscles and less robust Qi and Blood should receive needles inserted to a depth of 2 Fen. However, even so, one must apply flexibility (*Jing Quan*, principle and flexibility), avoiding rigid adherence to fixed rules. For persons of average build, the depth should be酌情ly determined within the range of 2 to 3 Fen.
Well (Jing) points are where Qi emerges, Stream (Ying) points are where it flows, Shu (Shu) points are where it pours, Jing (Jing) points are where it travels, He (He) points are where it converges, and Yuan (Yuan) points are its source. In Spring, Ying points are indicated; in Summer, Shu points are indicated; in Autumn, He points are indicated; in Winter, Jing points (and Jian points, referring to specific applications or variations) are indicated. For Zang organ diseases, Shu points are needled; for Fu organ diseases, He points are needled; for diseases of both Zang and Fu organs, Yuan points may be needled. Generally, the muscle tissue around Jing points is shallow, and deep needling is traditionally contraindicated.
[Note] Jing, Ying, Shu, Jing, He, and Yuan are the names of acupoints on the twelve meridians. The Yang meridities of the hands and feet possess Yuan points, whereas the Yin meridities do not have separate Yuan points; the Shu point of a Yin meridian serves as its Yuan point. "Where it emerges" is the Well (Jing), likened to water springing forth; "where it flows" is the Stream (Ying), likened to a small stream; "where it pours" is the Shu (Shu), likened to water pouring in; "where it travels" is the Jing (Jing), likened to a flowing river; "where it converges" is the He (He), likened to waters meeting; and "Yuan" is likened to the source of water. Needling Ying points in Spring targets collaterals located between the muscle bundles, requiring shallow insertion. Needling Shu points in Summer targets fine collaterals (Sun Luo) above the skin and muscle. Needling He points in Autumn also targets collaterals between muscle bundles, similar to Spring. Needling Jing points in Winter targets the area below the fine collaterals, requiring deeper insertion and retention because Cold Qi enters the Zang organs during winter. Both Jing and Yuan points are suitable for needling various diseases across all Hand and Foot Yin and Yang meridians, though depths vary and cannot be exhaustively listed. This represents the general principle of seasonal acupuncture, passed down since ancient times.