Mencius - Book 2, Part 2, Chapter 6

Mencius, occupying the position of a high dignitary in Ch'î, went on a mission of condolence to T'ang. The king also sent Wang Hwan, the governor of Kâ, as assistant-commissioner. Wang Hwan, morning and evening, waited upon Mencius, who, during all the way to T'ang and back, never spoke to him about the business of their mission.

Kung-sun Ch'âu. said to Mencius, 'The position of a high dignitary of Ch'î is not a small one; the road from Ch'î to T'ang is not short. How was it that during all the way there and back, you never spoke to Hwan about the matters of your mission?' Mencius replied, 'There were the proper officers who attended to them. What occasion had I to speak to him about them?'
~ James Legge translation via nothingistic.org ~

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