左手头指火之子。
诸家诠注。以子字为传写之误。非也。言医者。以第一食指探病患之左
手寸脉。乃心脉也。阴阳应象大论云。南方生热。热生火。火生苦。苦生心。
夫心既为火之所生。独非火之子欤。
四十五动无他事。
四十五动无他事者。亦当准前九畴之数。须得四十五动不易。则无他
故矣。张世贤释谓其数之动法。不根据五行相克。非也。
三十一动忽然沉。顿饭却来还复此。
凡心脉当取之六菽之重。言其浮中即当见也。今诊得其脉于三十一
动止。忽然而沉。夫沉水也。必重手乃见。且顿饭之时。方得复浮而起。夫
心火也。三十一动。以五五除之。则余其六。六为水之成数。以六五除之
则余其一。一为水之生数。合生成之数俱水。洁古曰。火得水而灭也。张
世贤谓三十一动。轮在肺上。肺上见沉。乃金生水。水渐盛。则火灭。觉太
牵强。
按经云。左手寸口脉。偏动。乍大乍小不齐。从寸口至关。关至尺。三部之
位。处处动摇。各异不同。其人病仲夏传之此脉。桃花落而死。
春中诊得夏须忧。夏若得之秋绝体。秋脉如斯又准前。冬若候之春必死。
若春中诊得此脉。则奉长者少矣。夏若诊得此脉。则奉收者少矣。秋若
诊得此脉。则奉藏者少矣。冬若诊得此脉。则奉生者少矣。张世贤谓三
月者。天道小变之节。亦未必然。今则准四气调神论释之。方合经旨。
左手食指所诊部位为心脉，属火之子。
各家注解认为“子”字是传抄错误，这种观点是不对的。这里的意思是说，医生用第一根食指探查患者左手的寸口脉，这就是心脉。《素问·阴阳应象大论》中说：“南方生热，热生火，火生苦，苦生心。”既然心是由火所生，难道不是火的儿子吗？
脉搏跳动四十五次且无其他异常。
所谓脉搏跳动四十五次且无其他异常，也应当依据前文九宫数的规律，必须保持四十五次跳动不变，才没有其他的病变。张世贤解释说是因为脉动的数量法则不根据五行相克的原理，这种说法是不对的。
脉搏跳动三十一下后突然变沉，一顿饭的时间后又恢复原状。
凡是诊察心脉，应当用相当于六粒豆子重量的力度按压，意思是浮取和中取时就能见到脉象。现在诊察发现脉搏在跳动三十一下时停止，突然变得沉伏。沉脉属水，必须重手按压才能见到。而且经过一顿饭的时间，脉象才重新浮起并恢复常态。心属火，三十一除以五的倍数（五五二十五），余数为六。六是水的成数；以六和五相除（六五三十），余数为1。一是水的生数。合起来生成之数皆属水。洁古（张元素）说：“火遇到水就会熄灭。”张世贤认为三十一动对应肺经，肺属金，金见沉脉乃金生水，水气渐盛则火灭，觉得这种解释太牵强。
按经典记载：左手寸口脉，如果偏侧搏动，忽大忽小且不整齐，从寸口至关部，关部至尺部，三部的位置上处处动摇，各不相同。这种人如果在仲夏出现这种脉象，等到桃花凋落时就会死亡。
如果在春季诊得这种脉象，夏季就会有忧患；如果在夏季诊得这种脉象，秋季身体就会衰绝；秋季脉象如此也遵循前面的规律；如果在冬季诊得这种脉象，春季必然死亡。
如果在春季诊得这种脉象，那么负责生长之气就少了；如果在夏季诊得这种脉象，那么负责收敛之气就少了；如果在秋季诊得这种脉象，那么负责闭藏之气就少了；如果在冬季诊得这种脉象，那么负责生发之气就少了。张世贤认为三个月是天道轻微变化的节气，也不一定是这样。现在则依据《素问·四气调神大论》来解释，才符合经典的本意。
The position examined by the index finger on the left hand corresponds to the Heart pulse, which is the "son" of Fire.
Various commentaries interpret the character "Zi" (Son) as a transcription error, but this is incorrect. It means that when the physician uses the first index finger to palpate the Cun (Inch) pulse at the left wrist, it is the Heart pulse. The *Suwen: Yin-Yang Yingxiang Dalun* states: "The South generates Heat; Heat generates Fire; Fire generates Bitterness; Bitterness generates the Heart." Since the Heart is generated by Fire, is it not the son of Fire?
Forty-five beats without other abnormalities.
Regarding forty-five beats without other abnormalities, one should also refer to the numerical principles of the Nine Categories mentioned earlier. The pulse must maintain forty-five beats consistently to indicate no other pathology. Zhang Shixian's explanation that the number of beats does not follow the principle of Five Elements overcoming each other is incorrect.
After thirty-one beats, the pulse suddenly becomes Deep; after a meal, it returns to its previous state.
When examining the Heart pulse, one should apply pressure equivalent to the weight of six beans, meaning the pulse should be visible with light and moderate pressure. However, in this case, the pulse stops or changes after thirty-one beats and suddenly becomes Deep. A Deep pulse belongs to Water and requires heavy pressure to be felt. Moreover, it takes about the time of a meal for the pulse to float up again and return to normal. The Heart belongs to Fire. Thirty-one divided by five (5x5=25) leaves a remainder of six. Six is the completed number of Water. Thirty-one divided by six and five (6x5=30) leaves a remainder of one. One is the generative number of Water. Combining these generative and completed numbers, they all point to Water. Jiegu (Zhang Yuansu) stated: "Fire is extinguished by Water." Zhang Shixian argued that thirty-one beats correspond to the Lung meridian; seeing a Deep pulse in the Lung (Metal) generates Water, causing Water to become strong and extinguish Fire, but he found this explanation too forced.
According to the classics: If the Cun Kou pulse on the left hand beats unevenly, fluctuating between large and small and irregular, shaking everywhere from the Cun position to the Guan position, and from the Guan position to the Chi position, with each of the three positions showing different movements, such a person will die when peach blossoms fall if this pulse appears in mid-summer.
If this pulse is diagnosed in Spring, there will be worry in Summer; if diagnosed in Summer, the body will deteriorate in Autumn; the pattern in Autumn follows the previous rules; if diagnosed in Winter, death will occur in Spring.
If this pulse is found in Spring, the Qi responsible for growth will be deficient; if found in Summer, the Qi responsible for harvesting/receiving will be deficient; if found in Autumn, the Qi responsible for storing will be deficient; if found in Winter, the Qi responsible for generating/nurturing will be deficient. Zhang Shixian claimed that the three months represent minor seasonal changes in the Heavenly Dao, but this is not necessarily true. Currently, interpreting this based on the *Suwen: Siqi Tiaoshen Dalun* aligns better with the intent of the classics.