According to the geomantic theory, there are three things in the grave that cannot be changed, and there is milk gas that cannot be changed. What does this (milk gas) mean and what shape does it take?

According to the geomantic theory, there are three things in the grave that cannot be changed, and there is milk gas that cannot be changed. What does this (milk gas) mean and what shape does it take? thank you If you think the ancestral grave is not good and want to be reburied, you must pay attention to three things, and you can't change it indiscriminately:

First, open the grave to see the tortoise and snake. This is an angry gathering, so it cannot be changed;

Second, there is heating or milk gas or fog in the soil, which is angry and cannot be changed;

Third, wisteria has intercourse, and the tomb cannot be changed.

Heating and fog are easy to understand. Milk gas just stays on the soil layer at the bottom of the tomb, which is similar to not rising. In fact, it is the slight heat emitted by the soil. Such a place is "angry" and a treasure.