Jiǎ

The ten heavenly stems begin here. 甲 (Jiǎ) is yang wood, and because each of the five elements takes a yang and then a yin stem, 乙 follows as its partner. 三命通會 卷二 calls it 十干之首, the head of the ten, thunder and dragon in the sky and a roof beam on the ground. Anyone whose day pillar has 甲 on top has it as day master, the stem from which the rest of the chart gets named.

滴天髓 pictures a trunk that rises level with the sky, and its commentary reads the second phrase through family: fire is wood's child, and strong wood that has fire spreads and flowers. Spring wood, it says, helps fire and cannot tolerate metal, while autumn wood helps metal and cannot tolerate earth. The Dragon and Tiger are the branches 辰 and 寅. If fire crowds the chart, sitting on 辰 can hold it in check, and if water crowds it, sitting on 寅 can take the flood in.

Practitioners name everything else from this stem, so for 甲 a 丙 is Eating God, a 庚 is Seven Killings and a 己 is Direct Wealth. 淵海子平 uses 甲 as the specimen for its table of names. The verse itself turns on season and seat, which is why a reader looks first at the month and at the branch under the day. The upright, tree-like 甲 person of popular modern books is a later extension, since this verse describes a tree and its surroundings.