《隋书·列传·卷六》
过了一年多，炀帝亲下手诏说： 玉石因为光洁玉润，丹紫不能超过它的质地；松柏耐寒，霜雪不能凋零它的风采。
岁余，帝下手诏曰： 玉以洁润，丹紫莫能渝其质；松表岁寒，霜雪莫能凋其采。
More than a year later, Emperor Yang personally issued an edict saying: Jade is smooth and warm, and dan purple cannot surpass its texture; Songbai is cold-resistant, and frost and snow cannot wither its beauty.