geng-yin day pillar

庚 metal is the controlling element here and 寅 wood the controlled. The stage is Extinction, and 五行大義 uses a different and milder name for the same seat of metal: 受氣於寅, it receives breath at 寅. The older word looks forward to what comes next.

Three kinds of relation are stacked inside this branch. 甲 is Indirect Wealth, wood that metal controls; 丙 is Seven Killings, fire that controls metal; 戊 is Indirect Resource, earth that feeds metal. All three are yang like 庚, and the tables differ mainly over how many days each holds in the month, with 三命通會 writing 艮土 for the earth.

松柏木, Pine and Cypress Wood, is the 納音. 三命通會 卷一 writes 松柏干节, trunks and joints of those trees, and 喜秋冬, pleased by autumn and winter, the cold half of the year. Its label 破禄马 may mirror the one at 甲申, for 庚禄居申 in 神峰通考 sets the salary seat of 庚 at 申 and this branch faces 申 directly, but the chapter states no such rule.