Almost always quoted as the second half of a couplet:
一寸光阴一寸金，
寸金难买寸光阴 ('an inch of time is an inch of gold; an inch of gold cannot buy an inch of time'). The first half goes back to the Tang poet Wang Zhenbai
王贞白 (875-958) in
白鹿洞, and the longer pairing became a stock saying in Ming-Qing primers like
增广贤文.
