Chief Joseph was the leader of the Wallowa band of Nez Perce, which was a Native American tribe found in the interior Pacific Northwest region of the United States. Chief Joseph led his band during their forced removal of their ancestral lands. In his surrender speech, Chief Joseph employs various rhetorical devices. The most important of this is pathos. Chief Joseph makes an appeal to emotion when he describes the freezing cold, hunger and isolation his tribe suffered.
I could not find the excerpt or passage that is missing in your question so I cannot tell you what the rhetorical device is used in it but I would tell you something about them so you can find it by yourself.
Ethos, pathos and logos are rhetorical devices that are used in speech or literature in order to show in particular the idea of it.
Ethos is referring to credibility or trust and one of the main things of it is confidence and it can use many sources that are reproducing the main idea.
Pathos is referring to emotion and values. It is usually using vivid language and inspirational quotes or words.
Logos is referring to proof or logic of something with many statistics, case studies and many other.
The poet uses the archetypal symbol of the setting sun to highlight death in this excerpt. The setting sun means that the night will come soon - just like death means that life has ended.
