I can't find it on the internet, but I think it generally means that the river on the internet is particularly cold, the green on the road is lingering, the sunset in the flower lane is gradually setting, and the guests are particularly concerned (homesick) in a foreign land. They are usually sentimental when they are awake, and I am as sentimental as I am awake.

I don't know if it's right. The meaning of the two sentences before and after this poem is actually similar, but it is composed of inverted sentences with clever rhyme, which is more classic.