Confucius. Book 2, Chapter 23.
Book 2, Wei Chang
1. Tsze-chang asked whether the affairs of ten ages after could be known.
2. Confucius said, "The Yin dynasty followed the regulations of the Hsia; wherein it took from or added to them may be known. The Chou dynasty has followed the regulations of the Yin: wherein it took from or added to them may be known. Some other may follow the Chou, but though it should be at the distance of a hundred ages, its affairs may be known."
Text source: Lun Yu, The Confucian Analects. Translated by James Legge.