The meaning of this sentence is that the sound of spring water in countless valleys spread to the outside of the pine forest, and several rows of yellow leaves of Qiu Shu extended from Yanmenguan.
He, Yin (He), said Wen Gou also, here is the valley.
The wild goose crossing is the wild goose gate.
This is a vivid description of the vast autumn scenery inside and outside the Great Wall.