Wake Forest University

Traditional:

61
　　清明內影，濁明外影；清明金水，濁明火日。僩。
Translation:
Clear brightness manifests as an interior image, and turbid brightness manifests as an exterior image. Clear brightness pertains to metals and water. Turbid brightness pertains to fire and the sun.
Xian
Commentary:

When Zhu Xi mentions "metals" here, he must be speaking of polished metal surfaces that mirror things so that they appear to us as "inside the looking glass." The undisturbed surface of a container full of water also acts as a reflective surface, and one may see the moon "in" the depths of the pond. From a Western perspective, "clear brightness" refers to reflected light, and "turbid brightness" refers to direct sources of illumination.