These reflect the Chinese medical philosophy that disease comes from the mind, so that curing the mind is the best remedy. Pretty scary! The crucial feature of divination poems is that people believe the spirit will invisibly guide the person seeking advice to choose the correct poem.
籤詩的奧妙之處，就是人們相信神明會在冥冥中引導求籤的人抽到正確籤詩。