Mencius. Book 4, Part 1, Chapter 15.
Book 4, Le Low. Part 1.
1. Mencius said, "Of all the parts of a man's body there is none more excellent than the pupil of the eye. The pupil cannot be used to hide a man's wickedness. If within the breast all be correct, the pupil is bright. If within the breast all be not correct, the pupil is dull.
2. "Listen to a man's words and look at the pupil of his eye. How can a man conceal his character?"
Text source: The Works of Mencius. Translated by James Legge.