《后汉书·列传·李固列传》
古时尧死之后，舜仰慕三年，坐下就看见尧在墙边，吃饭就看见尧在羹边。
昔尧殂之后，舜仰慕三年，坐则见尧于墙，食则睹尧于羹。
In ancient times, after Yao died, Shun mourned him for three years. When he sat down, he saw Yao by the wall, and when he ate, he saw Yao in the soup.