Mencius - Book 5, Part 2, Chapter 4B

Wan Chang said, 'Here now is one who stops and robs people outside the gates of the city. He offers his gift on a ground of reason, and does so in a manner according to propriety; would the reception of it so acquired by robbery be proper?'

Mencius replied, 'It would not be proper. in "The Announcement to Kang" it is said, "When men kill others, and roll over their bodies to take their property, being reckless and fearless of death, among all the people there are none but detest them:" thus, such characters are to be put to death, without waiting to give them warning. Yin received this rule from Hsiâ and Châu received it from Yin. It cannot be questioned, and to the present day is clearly acknowledged. How can the grift of a robber be received?'
~ James Legge translation via nothingistic.org ~

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