Geng Jin was born in, referring to the word Geng in the eight characters. He was born in Mitsuki (in April of the lunar calendar).
C doesn't melt gold, which means that although there is C fire in the eight characters, it won't melt Geng gold, because Geng gold is hard and refractory. At the same time, stagnant water can restrict C fire and play a balancing role.
The second choice is bentonite, and the third choice is fire, which shows that bentonite and fire have a certain auxiliary effect on the five elements of Geng Jin.
Ding Huo must be used to support the development of a gold bureau, that is to say, the gold in the eight characters is strong, and Ding Huo can restrain Geng Jin and play a certain balancing role.
Generally speaking, the meaning of this passage is: Geng Jin was born in Mitsuki. Although there is fire C in the eight characters, it will not melt Geng Jin, because Geng Jin is hard and difficult to melt. At the same time, stagnant water can restrict C fire and play a balancing role. Bentonite and c-fire have certain auxiliary effects on Geng Jin's five elements. If the metal in the eight characters is very strong, it needs Ding Huo to balance it.