What does it mean to be buried by law?

This burial method is called dragonfly water cave, which means taking care of both ends! I hope that future generations will have all the best and smooth sailing. However, we must pay attention to this burial method. The top of the coffin must be paved with loess, and other materials such as cement cannot be paved, otherwise it will become a cave. The geomantic omen of this cave that the landlord saw has been broken, but it is not clear what kind of influence it will have on future generations!