Refers to the dragon and tiger in the cave, slightly looming, closing and closing, bypassing the water in the cave. Such as shrimp whiskers and goldfish. Xu Shanji, "what should the son of man know? The water law says, "He who drains water has mountains on the top and water on the bottom. Although there is no dripping spring, it is also called water. When it rains, there is water dripping, but when the rain stops, there is no water. "Generally speaking, the method of Feng Shui is to take water as the first priority and take water as the shape of life, so it is called external air. If there is external gas, there is internal gas. Guo Pu's "Buried Sutra" refers to this. So it's always good to have water around the cave. Although the mainstream water is invisible and looming, feng shui experts pay attention to one inch high and one inch high, so dry running water is also one of the water. If there is, it is clear that Long Mai's letting go, the gathering of true qi, and the place where it is fenwei, is the place where the real dragon is tied. Therefore, feng shui experts believe that low water has the function of binding qi with bounded veins, and the left and right acupuncture points are close to each other, which is warm and calm. It is a land with auspicious value. The dragon owner will get fat in his early years, and the dry water will not grow straight, or the competition will be in a state of dumping. This is unlucky.