《内经》曰∶病有浮沉，刺有浅深，各正其理。然春夏为阳，其气在外，人气亦浮，凡
刺者故浅取之；秋冬为阴，其气在内，人气在藏，凡刺者故当深取之。又言春夏各致一阴，
秋冬各致一阳。秋冬各致一阳者，谓春夏为阳，谓阴所养，故刺之各致一阳。春夏温，必致
一阴，谓下针深，刺至肾肝之部，得其气，针便出之，是以外持之阴也；秋冬寒必致一阳，
致一阳者，谓下针浅，则刺至心肺之部，得气推而内之，良久出针，是推内之阳也，《素问
》曰∶春夏养阳，秋冬养阴故也。
凡欲下针，先以左手大指，掐于穴上，掐令多时，令患人呼十息，然后用右手持针，用
力之，取穴则有准，入穴既定，撒手停针十息，号曰天才，待少时再进针五分，根据前停针
，住手十息，号曰地才，不可便起，少待一二时，方可出针，号曰人才，乃可泻也。
凡下针待气，要上行闭其下，要下行闭其上，进针从辰至巳，退针巳至午未，进针则左
捻，退针则右捻动也。
敬曰 下水船中之橹，独如赤凤摇头，别辩迎随逆顺，休时慢法徒求。
凡下针飞气，至关要去处回拨者，将针散漫伏之，如船中之舵，左右随其气，轻而拨，
其气自交，周身遍体夺流，不失其所矣。如气不行，将针动伸动提。
敬曰 苍龙摆尾气交流，血气夺流遍体周。任他身上千般病，一插教他即便瘳。
《黄帝内经》说：疾病有表浅和深重的区别，针刺也有浅刺和深刺之分，应当各自遵循其正确的道理。然而春夏季节属阳，阳气在外，人体的气血也浮越于外，所以凡是用针治疗时，通常采用浅刺的方法；秋冬季节属阴，阴气在内，人体的气血潜藏于内脏，所以凡是用针治疗时，应当采用深刺的方法。又提到“春夏各致一阴，秋冬各致一阳”。所谓“秋冬各致一阳”，是指春夏虽然属阳，但其中蕴藏着被阴气所涵养的阳气（意指需引阴中之阳），所以在针刺时要引导出阳气。春夏气候温暖，必须引导入阴气，意思是下针要深，刺至肾、肝所在的部位，得气后，随即拔针，这是为了固护体表的阴气；秋冬气候寒冷，必须引导入阳气，所谓“致一阳”，意思是下针要浅，刺至心、肺所在的部位，得气后推针深入，停留较长时间再出针，这是为了推纳体内的阳气。《素问》说：春夏养阳，秋冬养阴，就是这个道理。
凡是准备下针时，先用左手大拇指，掐按在穴位上，掐压一段时间，让患者呼吸十次，然后用右手持针，用力进针，取穴就会准确。进入穴位后，松开手让针静止十次呼吸的时间，称为“天才”；等待片刻后再进针五分，按照前面的方法停针，手停止动作十次呼吸的时间，称为“地才”；不可立即起针，稍待一会儿，方可出针，称为“人才”，然后才可以施行泻法。
凡是下针候气时，若要使气上行，就要闭塞下部；若要使气下行，就要闭塞上部。进针的时间从辰时到巳时，退针的时间从巳时到午时、未时。进针时向左捻转，退针时向右捻转活动。
董宿评曰：这就像下水船中的橹，又像赤凤摇头，另外辨别迎随逆顺的手法，若是时机不对或违背法则，徒劳无功。
凡是下针行气，到达关键部位需要回拨导气时，将针散漫伏贴，就像船中的舵一样，左右随着气流的方向，轻轻拨动，气机自然交汇，周身遍体气血流畅，不失去其应有的运行规律。如果气不行走，就动针、伸针、提针。
董宿评曰：苍龙摆尾手法能使气机交流，血气流畅遍及全身。任凭他身上有多少种疾病，一针插下教他立刻痊愈。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: Diseases manifest as either superficial or deep, and acupuncture needling should be either shallow or deep accordingly, each adhering to its proper principle. However, spring and summer belong to Yang; their Qi is external, and human Qi also floats outward. Therefore, in all cases of needling, one should generally adopt shallow insertion. Autumn and winter belong to Yin; their Qi is internal, and human Qi resides within the Zang organs. Therefore, in all cases of needling, one should adopt deep insertion. It is also stated that "in spring and summer, one must attain a Yin [state]; in autumn and winter, one must attain a Yang [state]." The phrase "attaining a Yang state in autumn and winter" refers to the fact that although spring and summer are Yang, they contain Yin nourishing Yang; thus, needling aims to guide out Yang. In warm spring and summer, one must attain Yin, meaning the needle should be inserted deeply to the regions of the Kidney and Liver. Upon obtaining Deqi (arrival of Qi), the needle is withdrawn immediately, thereby securing the Yin at the exterior. In cold autumn and winter, one must attain Yang. "Attaining Yang" means inserting the needle shallowly to the regions of the Heart and Lung. Upon obtaining Deqi, the needle is pushed deeper, retained for a long time, and then withdrawn, thereby pushing inward Yang. The *Suwen* (Basic Questions) states: "Nourish Yang in spring and summer, nourish Yin in autumn and winter." This is the rationale.
Before inserting the needle, first use the thumb of the left hand to press firmly on the acupoint for some time, allowing the patient to breathe ten cycles. Then, hold the needle with the right hand and insert it with force; this ensures accurate point selection. Once the needle is established in the point, release the hand and let the needle remain still for ten breath cycles, termed "Tiancai" (Heavenly Talent). After a short while, advance the needle by five fen. Pause again according to the previous method, stopping hand movement for ten breath cycles, termed "Dicai" (Earthly Talent). Do not withdraw the needle immediately; wait a moment before withdrawing it, termed "Rencai" (Human Talent), after which the draining (Xie) method may be applied.
When waiting for Qi after needling, if the intention is to move Qi upward, occlude the lower part; if the intention is to move Qi downward, occlude the upper part. Advancing the needle occurs from Chen hour to Si hour; withdrawing the needle occurs from Si hour to Wu and Wei hours. Advancing involves leftward twisting; withdrawing involves rightward twisting and movement.
Dong Su comments: This is like the oar in a boat going downstream, resembling the swaying head of a red phoenix. One must distinguish between welcoming and following versus opposing and reversing techniques. If the timing is wrong or the method violates principles, the effort is futile.
When guiding Qi during needling, especially when reaching critical areas requiring back-and-forth manipulation, scatter the needle gently as if it were the rudder of a boat, moving left and right following the flow of Qi. Gently manipulate it, and the Qi will naturally converge, causing blood and Qi to flow smoothly throughout the body without losing their proper course. If Qi does not move, move, extend, or lift the needle.
Dong Su comments: The Canglong Baiwei (Green Dragon Swinging Tail) technique facilitates the flow of Qi, allowing blood and Qi to circulate throughout the entire body. Regardless of the myriad diseases afflicting the body, a single insertion can bring about immediate recovery.