Mencius - Book 5, Part 1, Chapter 1A

Wan Chang asked Mencius, saying, 'When Shun went into the fields, he cried out and wept towards the pitying heavens. Why did he cry out and weep?' Mencius replied, 'He was dissatisfied, and full of earnest desire.'

Wan Chang said, 'When his parents love him, a son rejoices and forgets them not. When his parents hate him, though they punish him, he does not murmur. Was Shun then murmuring against his parents?' Mencius answered, 'Ch'ang Hsî asked Kung-ming Kâo, saying, "As to Shun's going into the fields, I have received your instructions, but I do not know about his weeping and crying out to the pitying heavens and to his parents."

Kung-ming Kâo answered him, "You do not understand that matter." Now, Kung-ming Kâo supposed that the heart of the filial son could not be so free of sorrow. Shun would say, "I exert my strength to cultivate the fields, but I am thereby only discharging my office as a son. What can there be in me that my parents do not love me?"

'The Tî caused his own children, nine sons and two daughters, the various officers, oxen and sheep, storehouses and granaries, all to be prepared, to serve Shun amid the channeled fields. Of the scholars of the kingdom there were multitudes who flocked to him. The sovereign designed that Shun should superintend the kingdom along with him, and then to transfer it to him entirely. But because his parents were not in accord with him, he felt like a poor man who has nowhere to turn to.
~ James Legge translation via nothingistic.org ~

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