Complete Compendium of Five-Star and Three-Fate Astrology, Volume 1 (1657) - Page 12

○ Fixed Configurations of the Three Harmonies of the Twelve Branches

The "Three Harmonies" (sanhé 三合) are groups of three Earthly Branches that, when appearing together, create a powerful resonance of a specific element. These are often used in calculating compatibility or seasonal strength.

Shen, Zi, and Chen combine to form the Water cycle These correspond to the Monkey, Rat, and Dragon.
Hai, Mao, and Wei combine to form the Wood cycle These correspond to the Pig, Rabbit, and Goat.
Yin, Wu, and Xu combine to form the Fire cycle These correspond to the Tiger, Horse, and Dog.
Si, You, and Chou combine to form the Metal cycle These correspond to the Snake, Rooster, and Ox.
Chen, Xu, Chou, and Wei combine to form the Earth cycle These four branches represent the transitional periods at the end of each season.

○ Mutual Clashes of the Twelve Branches

Mutual Clashes (xiāngchōng 相冲) represent oppositional forces. In the circular arrangement of the zodiac, these branches sit directly across from one another, indicating conflict or dynamic change.

Zi and Wu clash Rat and Horse; North and South.
Yin and Shen clash Tiger and Monkey; Northeast and Southwest.
Mao and You clash Rabbit and Rooster; East and West.
辰 (Chen) and 戌 (Xu) clash Dragon and Dog; Southeast and Northwest.
Si and Hai clash Snake and Pig; Southeast and Northwest.
Chou and Wei clash Ox and Goat; Northeast and Southwest.

○ Yin and Yang Affiliations of the Twelve Branches

Zi, Yin, Chen, Wu, Shen, and Xu belong to Yang These are the odd-numbered branches, associated with active, masculine, or light energy.
Chou, Mao, Si, Wei, You, and Hai belong to Yin These are the even-numbered branches, associated with receptive, feminine, or dark energy.

○ Five Element Affiliations of the Twelve Branches

Yin and Mao belong to the East and the element of Wood.
Si and Wu belong to the South and the element of Fire.
Shen and You belong to the West and the element of Metal.
Hai and Zi belong to the Northern Water?.