Eight-Mansion Grand Wandering Years and Xuan Kong Da Gua Feng Shui Theory

First published on the WeChat public platform "Daoist Yinfu Culture"2019-09-06. Illustrations omitted.

The Eight-Mansion Grand Wandering Years is a relatively common feng shui art among the people. Xuan Kong Da Gua and Eight Mansion share consistent underlying principles — in fact, the essence of Xuan Kong Da Gua can be regarded as an extension of Eight-Mansion theory.

According to the Nine Palaces, the hexagram periods of Xuan Kong's grand fortunes are actually derived as:

Kun is 1 — Tanlang
Xun is 2 — Jumen
Li is 3 — Lucun
Dui is 4 — Wenqu
Gen is 6 — Wuqu
Kan is 7 — Pojun
Zhen is 8 — Fuxing
Qian is 9 — Bi

The hexagram periods of Xuan Kong Da Gua hold that combining to five, ten, fifteen, or generating constitutes an auspicious judgment — in practice this is identical to the calculations of Eight-Mansion Grand Wandering Years.

In Eight Mansion, eight terms are used to express the relationships: Shengqi (Life-qi), Wugui (Five Ghosts), Yannian (Extended Years), Liusha (Six Sha), Huohai (Calamity), Tianyi (Heavenly Doctor), Jueming (Severed Fate), and Fuwei (Repetitive Position). Among these:

Shengqi is Tanlang
Yannian is Wuqu
Tianyi is Jumen
Fuwei is Zuofu
Huohai is Lucun
Liusha is Wenqu
Wugui is Lianzhen
Jueming is Pojun

And in Eight-Mansion calculations, the numbers taken for the hexagrams are exactly the same as those taken for Xuan Kong Da Gua's hexagram periods.

The Shengqi Tanlang position is when the two hexagrams' periods combine to generate — for example:
Qian 9 − Dui 4 = 5
Gen 6 − Kun 1 = 5
Kan 7 − Xun 2 = 5
Zhen 8 − Li 3 = 5

And Jumen, that is Tianyi, is when the two hexagrams sum to five or fifteen — for example:
Qian 9 + Gen 6 = 15
Dui 4 + Kun 1 = 5
Kan 7 + Zhen 8 = 15
Li 3 + Xun 2 = 5

Wuqu, that is Yannian, is when the two hexagrams sum to ten — for example:
Qian 9 + Kun 1 = 10
Gen 6 + Dui 4 = 10
Kan 7 + Li 3 = 10
Zhen 8 + Xun 2 = 10

Zuofu, that is Fuwei, is very simple: two identical hexagrams meeting.

Then the rest do not satisfy the conditions of summing to five, ten, fifteen, or generating. Briefly:
Lucun Huohai: the sum yields 1 or 9
Wenqu Liusha: the sum yields 4 or 6
Lianzhen Wugui: the sum yields 3 or 7
Pojun Jueming: the sum yields 2 or 8

So if one directly uses the eight directions of Eight Mansion and takes the Luo numbers of the Earlier-Heaven trigrams of the directions to calculate the relationships between different targets, that is the traditional Eight-Mansion method.

And if one uses the sixty-four hexagrams as a full celestial circuit, obtains the resulting hexagram from combining each hexagram's own upper and lower trigrams, and takes the Luo numbers of the Earlier-Heaven trigram of the resultant hexagram to calculate the relationships between different targets, that is the method of Xuan Kong Da Gua.