 In 200, when Cao Cao was away attacking Liu Bei in Xu Province, Tian Feng urged Yuan Shao to seize the opportunity to launch an attack on Cao Cao's base at Xu.However, Yuan Shao refused and said that he was more concerned about his son, who was sick.The frustrated Tian Feng hit the ground with his staff and said, "What a pity that he let a rare opportunity slip by just because of a child's illness!"