As the book says, "the thief comes first, and the mother-in-law comes later."
The chalcedony sutra says: "If you explore the mountains, if they are all fierce, you will move to the burial house and the people will be thieves;" If all the mountains are auspicious, the main family will attract thieves and always lose. "
The probe means that the front mound is low and the back mound is slightly high and round, like a person sticking his head out to show peeping. There is also the statement of Yangzhai Probe Mountain, which is difficult to crack.