Answer: From user weberollinwehatin: "Sitting Bull, a holy man, statesman, and warrior of the Hunkpapa Lakota, had been praying in the days prior to the battle, and had a vision in which he saw soldiers falling like grasshoppers; a voice said to him, "I give these to you because they have no ears." This part of the passage shows the bias in part of the story, he was shown through his dream a possible outcome and a weakness to the other, and thus he was able to make a plan and set warriors out to protect and attack. When the author uses words like "vision" and "a voice" it gives an ominous feel and shows the readers that this was before the battle giving it a sense of bias.
Explanation: Another user appeared to have read the story and posted this as an example answer along with their own explanation. Good luck!