Confucius. Book 3, Chapter 11.
Book 3, Pa Yih.
Some one asked the meaning of the great sacrifice. The Master said, "I do not know. He who knew its meaning would find it as easy to govern the kingdom as to look on this;" ‹ pointing to his palm.
Text source: Lun Yu, The Confucian Analects. Translated by James Legge.