《周书·列传·卷二十二》
哪能改变礼制，违背天性呢! 当时人们都不能说服他，柳庆就拿草垫当席子，拿土块作枕头，替生父服满丧期。
岂容夺礼，乖违天性！ 时论不能抑，遂以苫块终丧。
How could we change the rituals and violate our nature? Nobody could persuade him then. Liu Qing used straw mats as his mat and earth as his pillow, and served the full mourning period for his father.