Black Elk on the topic of ancestors

There are many points within the book Black Elk Speaks where he talks of his grandfathers meaning his ancestors. In chapter three Black Elk becomes very sick and he has a vision. In this vision two men descended from the sky carrying flaming spears and told Black Elk "Hurry! Come! Your Grandfathers are calling you!" As Black Elk and the men ascended they came upon a bay horse which took Black Elk to his Grandfathers. After the vision showed him some super natural horses, with manes made of lighting, blizzard winds, and vines, Black Elk came across a tepee made of clouds with rainbow door and within it were six old men sitting in a row. As they spoke to him they gave him the power of life and the power to destroy in the form of a wooden cup filled with water and a great bow respectively. They told him to take these things and his courage because "on earth a nation you shall make live, for yours shall be the power of the white giant's wings, the cleansing wind." Basically his ancestors are telling him that he will be the one to help his people. Then in chapter 21 Black Elk remembers the times that he talked to his ancestors and what they wanted him to do, to bring his people back into the great hoop. For many native american tribes their ancestors are the people they look to for guidance and to see what they should do next, they are of great impotence to most ever native tribe.