In these lines, the poet acknowledges the presence of Dorothy, his sister, along with him at the banks of the river. In her eyes and voice, he sees his younger version, bubbling with the same excitement and passion, which he once had. He seems to tell his sister, again, how nature has blessed humankind, and amid all this dreary world of selfish people, nature will prevail and maintain its supremacy over mortals like us. He reiterates how nature tells us to be selfless and enjoy the tranquility.