《论语·八佾篇》
孔子说： 夏朝的礼仪制度，我可以说一说，但是它的后代杞国不足以证明我的话；殷朝的礼仪制度，我能说一说，但它的后代宋国不足以证明我的话。
子曰： 夏礼吾能言之，杞不足征也；殷礼吾能言之，宋不足征也。
The Master said, "The ceremonial system of the Xia dynasty, I can describe. Its subsequent representatives, however, the K'i people, cannot furnish sufficient evidence. The ceremonial system of the Yin dynasty, I can describe. Its subsequent representatives, however, the Sung people, cannot furnish sufficient evidence.