Mencius - Book 5, Part 1, Chapter 6A

Wan Chang asked Mencius, saying, 'People say, "When the disposal of the kingdom came to Yü, his virtue was inferior to that of Yâo and Shun, and he transmitted it not to the worthiest but to his son." Was it so?' Mencius replied, 'No; it was not so. When Heaven gave the kingdom to the worthiest, it was given to the worthiest. When Heaven gave it to the son of the preceding sovereign, it was given to him. Shun presented Yü to Heaven.

'Seventeen years elapsed, and Shun died. When the three years' mourning was expired, Yü withdrew from the son of Shun to Yang-ch'ang. The people of the kingdom followed him just as after the death of Yâo, instead of following his son, they had followed Shun. Yü presented Yî to Heaven. Seven years elapsed, and Yü died. When the three years' mourning was expired, Yî withdrew from the son of Yü to the north of mount Ch'î. The princes, repairing to court, went not to Yî, but they went to Ch'î. Litigants did not go to Yî, but they went to Ch'î, saying, "He is the son of our sovereign;" the singers did not sing Yî, but they sang Ch'î, saying, "He is the son of our sovereign."
~ James Legge translation via nothingistic.org ~

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