Ask for poems or classical Chinese sentences containing "Xu"

So Jiang Ziya sold it for nothing, but it was taught by both civil and military. -Jin's "Bao Puzi" Life in March, eyes are sharp, you can laugh. -Qing Yu, nephew of the white tiger boy, less cases. -Tang Xuanzong's "Commanding the Imperial Clan" is a warm spring, but it is a rain. -Yucheng, Wang Song, "Send a Wood Servant to Quexu", in the morning twilight, Spring and Autumn Sun. -Yan Yanzhi's "Tao Zhengshi"