〔原文〕龟鳖行气法，以衣覆口鼻，不息九通，正卧。微微由鼻出纳气。愈鼻塞不通。
东向坐，仰头不息五通。以舌撩口中沫满二七咽，愈口干舌苦。
〔解说〕龟鳖行气法，以衣被覆盖口鼻，不息九通，采用正卧位，呼吸要匀细深长由
鼻出气和吸气。可治疗鼻塞不
通气。
面向东坐，仰头向日，不息九通，然后用舌头舐上 ，使口中产生唾液，咽下十四
次，可治口干舌燥和口苦。
小结∶
本篇龟鳖行气法和雁行气法、龙行气法、虾蟆行气法等，都是古人仿生而创立的导引
吐纳法。龟鳖是长寿动物，古人常以“鹤寿龟龄”祝福人们长寿。应用于气功则有“龟纳鼻息
，鹿运尾 ，以通任、督”等，龟鳖的呼吸极细极微，纳出无声，绵续如缕，似动非动，承先
启后，因此能步步永继，长寿百数年。仿效龟鳖行气，当亦能使人长寿。仿效方法有二∶一是仿
龟鳖形态，以衣被覆盖口鼻，如龟鳖缩颈壳中，二是仿效龟鳖呼吸，使呼吸由鼻出入，匀细深长，
直入丹田，以养生延年。以后称此功为龟息。强调以仿效龟鳖吸呼为主，不必拘泥于以衣被覆口鼻。
本篇第二段讲的是吸日精和咽唾液法，如能和龟鳖行气法结合，则收效更好。将本段放在
龟鳖行气法后可能还有取龟鳖行气，常面东朝日吸日精华，并以唾液养阴之义。
The Turtle and Softshell Turtle Qi Circulation Method involves covering the mouth and nose with clothing, holding the breath for nine cycles, lying flat on the back in a correct posture, and breathing slightly through the nose. It can cure nasal congestion.
Sit facing east, tilt the head back, and hold the breath for five cycles. Use the tongue to stir the saliva in the mouth until it is full, then swallow it fourteen times. This can cure dry mouth and bitter taste.
[Explanation] The Turtle and Softshell Turtle Qi Circulation Method involves covering the mouth and nose with a quilt or clothing, holding the breath for nine cycles, adopting a supine position, and breathing evenly, finely, deeply, and long through the nose. It can treat nasal obstruction.
Sit facing east, tilt the head back towards the sun, and hold the breath for nine cycles (Note: The original text mentions five cycles earlier; this section explains nine). Then use the tongue to lick the upper palate to generate saliva in the mouth, swallowing it fourteen times. This can treat dry mouth, parched tongue, and bitter taste.
Summary:
The Turtle and Softshell Turtle Qi Circulation Method, along with the Wild Goose Qi Circulation Method, Dragon Qi Circulation Method, and Toad Qi Circulation Method mentioned in this chapter, are all Daoyin (guiding and pulling) and Tunai (breathing regulation) methods created by ancient people based on biomimicry. Turtles and softshell turtles are longevity animals; ancient people often used the phrase "crane's lifespan and turtle's age" to bless people with longevity. In the application of Qigong, there are sayings such as "the turtle inhales through the nose, the deer moves the tail gate to unblock the Ren and Du meridians." The breathing of turtles and softshell turtles is extremely fine and subtle, silent upon inhalation and exhalation, continuous like a thread, seemingly moving yet still, connecting the past and future. Therefore, they can perpetually continue and live for hundreds of years. Imitating the Qi circulation of turtles and softshell turtles should also enable humans to achieve longevity. There are two methods of imitation: one is to imitate the posture of turtles and softshell turtles by covering the mouth and nose with clothing, as if they retract their necks into their shells; the other is to imitate their breathing, making the breath enter and exit through the nose, even, fine, deep, and long, going directly to the Dantian (lower abdomen energy center) to nourish life and prolong years. Later, this practice was called "Turtle Breath." It emphasizes imitating the breathing of turtles and softshell turtles as the main focus, without being rigidly attached to covering the mouth and nose with clothing.
The second paragraph of this chapter discusses absorbing the essence of the sun and swallowing saliva. If combined with the Turtle and Softshell Turtle Qi Circulation Method, the effect would be better. Placing this paragraph after the Turtle and Softshell Turtle Qi Circulation Method may also imply the meaning of turtles and softshell turtles facing east towards the sun to absorb solar essence during Qi circulation, and using saliva to nourish Yin.