一寸光阴一寸金

yī cùn guāng yīn yī cùn jīn

(saying) time is precious

one

cùn

a unit of length

guāng

light; ray (CL:道[dao4])

yīn

variant of 陰|阴[yin1]

one

cùn

a unit of length

jīn

gold