天以六为节。地以五为制。其生五。（天元纪大）
河图之教五十有五。而总其数为天五地六。分其数为天五地五。天五者、一三五七九。五奇也。地五者、二四六八
十。五耦也。奇以五乘五。五五二十五。耦以六乘五。五六三十。此所以天五地六也。然而阴阳交互。气运相乘。则天
气反以六。地气反以五。此六节五制之旨。轩岐所述也。盖两仪既奠。而后天以阳而化气。气本无形。凡六合无形化气
之阴阳。皆本于天气。以阴而成质。质处有形。凡六合有形成质之阴阳。皆本于地气。所谓五者。生长化收藏。而成木
火土金水是也。所谓六者。少阳阳明太阳厥阴少阴太阴。以奉寒暑燥湿风火是也。所谓六为节者。天以一元布行于地。
即本地之六位以分化气。是天以六为节也。所谓五为制者。地以坤顺承之化。即本天之五行以作成物。是地以五为制也。
总之天以五而干生。地以六而支生。以五加六而甲子生。天以五用六。地以六承五。此天施地生之大致。而六节五制之
妙义也。其生五者。原其初则五行实生于一气。由其后则万类皆生于五行。故五行有本生之理。有制用之道。其始也天
一生水。天一者纯刚之气也。纯刚之气为全体。故生水。水之为物。一阳居二阴之间。由静而动。由阴而阳。动而之阳。
故地二生火。水火既济。则形成而物畅。故天三生木。阳既畅发。则阳后生阴。自舒而敛。故地四生金。土居中位。成
乎四气。而成功位次反居其后者。土为万物之母。奉天而不居。故必于四气之既成。而后见之也。然土为中宫。为炉鼎。
能以水火为用。水火不得则相射。是以戊己之位。藏于水火。此坎纳六戊。离纳六己。所自来也。故戊己中宫为最尊。
布气育灵。为生物元始。所谓资生于坤也。故以是为南政。君临于上。而水木火金四脏之气环拱之。以其环拱。故谓之
北政。如臣面君也。至其地支辰戌丑未。居四余之偏。兼为四库者。盖以奠定四气。所以始万物终万物而告成功于物后
也。故天虽以五生土。而常以一先四。而首万物。一先四者。即五数之一。而首以土运之义也。此万物所以资始也。地
虽以十成土。而恒以二居五而终阴阳。二居五者。戊癸化火。而适终于地二之数也。此万物所以资生也。生生之本。制
用之道尽矣。
Heaven uses "six" as the measure of its cycles, and Earth uses "five" as the principle of its regulation. The generation of things originates from "five". (From *Tianyuan Ji Dalun*)
The numerical teaching of Hetu sums to fifty-five. Its total number is summarized as Heaven Five and Earth Six; its divided numbers are summarized as Heaven Five and Earth Five. "Heaven Five" refers to the five odd numbers: one, three, five, seven, nine. "Earth Five" refers to the five even numbers: two, four, six, eight, ten. The odds multiplied by five yield twenty-five (5x5); the evens multiplied by six yield thirty (6x5). This is the rationale behind "Heaven Five and Earth Six." However, when Yin and Yang interact and Qi movements multiply each other, Heavenly Qi manifests as "six," and Earthly Qi manifests as "five." This is the purport of "Six Cycles and Five Regulations," as expounded by Huangdi and Qibo.
Once the Two Modes (Liangyi) are established, post-heaven Qi transformation occurs through Yang Qi. Qi is inherently formless. All Yin-Yang transformations that are formless within the Six Harmonies originate from Heavenly Qi. Substance formation occurs through Yin Qi; substance exists in a tangible state. All Yin-Yang transformations that form tangible substances within the Six Harmonies originate from Earthly Qi. The so-called "Five" refers to Growth, Transformation, Harvest, Storage, which constitute Wood, Fire, Earth, Metal, and Water. The so-called "Six" refers to Shaoyang, Yangming, Taiyang, Jueyin, Shaoyin, and Taiyin, which correspond to Cold, Heat, Dryness, Dampness, Wind, and Fire. The phrase "Six as Cycles" means that Heaven distributes the One Yuan Qi onto Earth, utilizing the local six positions to differentiate Qi transformation; thus, Heaven uses "six" as the cycle. The phrase "Five as Regulations" means that Earth, following Kun virtue, receives Heaven's transformation, utilizing the Heavenly Five Elements to accomplish things; thus, Earth uses "five" as the regulation.
In summary, Heaven generates via the Stems using "five," and Earth generates via the Branches using "six"; combining "five" and "six" produces the Jiazi cycle. Heaven employs "five" with "six," and Earth receives "five" with "six." This is the general principle of Heaven bestowing and Earth generating, and the profound meaning of "Six Cycles and Five Regulations." Regarding "Its generation comes from five," tracing back to the origin, the Five Elements actually arise from One Qi; looking forward, all categories of life arise from the Five Elements. Thus, the Five Elements have both the principle of original generation and the way of regulatory application. Initially, Heaven One generates Water. "Heaven One" is pure Gang (firm/strong) Qi. Pure Gang Qi constitutes the whole, hence it generates Water. Water, as an entity, has one Yang residing between two Yins, moving from stillness to motion, from Yin to Yang, moving towards Yang; therefore, Earth Two generates Fire. When Water and Fire achieve mutual interaction (Ji Ji), form is established and things flow freely; therefore, Heaven Three generates Wood. Once Yang is fully expressed, Yin is generated after Yang, transitioning from expansion to contraction; therefore, Earth Four generates Metal. Earth occupies the central position, completing the four Qi elements. Its success appears later because Earth is the mother of all things, serving Heaven without claiming credit, so it manifests only after the four Qi elements are complete.
However, Earth resides in the Central Palace, acting like a furnace or tripod, capable of utilizing Water and Fire. If Water and Fire do not function properly, they repel each other. Therefore, at the positions of Wu and Ji, they are hidden within Water and Fire. This is the origin of Kan Gua containing Liu Wu and Li Gua containing Liu Ji. Thus, Wu-Ji Central Palace is most revered, distributing Qi to nourish spirits, serving as the primordial beginning of creation, which is what is meant by "nourished by Kun." Hence, this serves as Southern Politics, with the Sovereign ruling above, while the Qi of the four Zang organs—Water, Wood, Fire, and Metal—surround and support it. Because they surround and support, it is called Northern Politics, like ministers facing the sovereign. As for the Earthly Branches Chen, Xu, Chou, and Wei, occupying the peripheral positions of the four residual Qi and serving as the four Storehouses, they likely serve to stabilize the four Qi elements, thus beginning all things and ending all things, announcing success after the completion of things. Therefore, although Heaven generates Earth using five, it often places "one" before "four" to lead all things. "One preceding four" refers to the "one" in the number five and the meaning of leading with Earth Qi. This is why all things receive their origin. Although Earth completes Earth using ten, it constantly places "two" at "five" to conclude Yin and Yang. "Two at five" refers to Wu and Gui transforming into Fire, which恰恰 concludes at the number of Earth Two. This is why all things receive their nourishment. The root of continuous generation and the way of regulatory application are fully exhausted here.