Confucius. Book 2, Chapter 5.
Book 2, Wei Chang
1. Mang I asked what filial piety was. The Master said, "It is not being disobedient."
2. Soon after, as Fan Ch'ih was driving him, the Master told him, saying, "Mang-sun asked me what filial piety was, and I answered him, ‹ 'not being disobedient.' "
3. Fan Ch'ih said, "What did you mean?" The Master replied, "That parents, when alive, should be served according to propriety; that, when dead, they should be buried according to propriety; and that they should be sacrificed to according to propriety."
Text source: Lun Yu, The Confucian Analects. Translated by James Legge.