From Du Fu's Book of Letters, "But before he conquered, he was dead, and the heroes cried on their coats." Lao Du experienced an Anshi Rebellion and was displaced all his life. At that time, his greatest wish was to get rid of the rebels, recover the lost land, and let the people no longer suffer from war. A "hero" should refer to someone who is committed to it. Du Fu is keen on political affairs. And the meaning of self-commitment.