1 as YuanJing, forms water, as Ren water. 3 as YuanXing, forms wood, as Jia wood. 5 as YuanQi, forms earth, as Wu earth. 7 as YuanShen, forms fire, as Bing fire. 9 as YuanQing, forms metal, as Geng metal.
纳甲阴阳之论 - DISCUSSING NAJIA YINYANG
“Adorning 9 through 1, left 3 right 7, 2-4 as shoulder, 6-8 as sufficient.”
9,1,3,7 odd as Yang, 6,4,8,2 even as Yin.
“Adorning 9 through 1”: Early Heaven Qian south, Kun north, Qian 9, Kun 1 entirely odd, as Yang. Qian NaJia, Kun NaYi as Yang.
“Left 3 right 7”: Early Heaven Li east, Kan west, Li 3, Kan 7 entirely odd, as Yang. Li NaRen, and Li as Wu, SanHe structure of YinWuXu fire frame. Kan NaGui, and Kan as Zi, SanHe structure of ShenZiChen water frame. Therefore, Li (Wu) Ren Yin Xu, Kan (Zi) Gui Shen Chen are Yang.
“2-4 as shoulder”: Early Heaven Dui as southeast, Xun southwest, Dui 4, Xun 2 as even therefore Yin. Dui NaDing, Dui also You, SanHe structure of SiYouChou metal frame. Xun NaXin, Therefore, Dui (You) Ding Ji Chou, Xun Xin are Yin.
“6-8 as sufficient”: Early Heaven Zhen as northeast, Gen southeast, Zhen 8, Gen 6 as even therefore Yin. Zhen NaGeng, Zhen also Mao, SanHe structure of HaiMaoWei wood frame. Gen NaBing, Therefore, Zhen (Mao) Geng Hai Wei, Gen Bing are Yin.
The above said derived from TaiSu "Supreme Essence" ("Lai"BuYi) Expediting Officer Scroll (ChuiGuanPian) prescribed “odd matches odd, even matches even, LuoShu first arrange Early Heaven”.