《黄帝内经·素问·六元正纪大论》
发现平野中的草皆低垂不起，柔软的树叶子皆背面翻转向外，高山之松被风吹作响，虎啸于山崖风峦之上，乃是木郁将发的先兆。
长川草偃，柔叶呈阴，松吟高山，虎啸岩岫，怫之先兆也。
I found that the grass in the plain was all drooping and could not be lifted, the soft tree leaves were all turned upside down and facing outward, the pines in the high mountains were blown by the wind, and the tigers roared on the cliffs and mountains, which were all signs of the onset of wood depression.