Mencius - Book 7, Part 1, Chapter 16

Mencius said, 'When Shun was living amid the deep retired mountains, dwelling with the trees and rocks, and wandering among the deer and swine, the difference between him and the rude inhabitants of those remote hills appeared very small. But when he heard a single good word, or saw a single good action, he was like a stream or a river bursting its banks, and flowing out in an irresistible flood.'

~ James Legge translation via nothingistic.org ~

 Go here to read the introductory post to this serialized version of the Works of Mencius.