Why flying bear?

Jiang, Shang, Ziya and flying bear. According to the Story of King Wu's Fall, Xibo dreamed of a tiger with wings. When he came to see his royal highness, the Duke of Zhou said that "the tiger with wings is flying bear" would lead to a saint, and the consequence would be a saint Jiang Shang. At that time, Jiang Shang was fishing on the bank of Weihe River. Later, "flying bear" was the symbol of the monarch's virtue.