力不从心

Origin and story

Ban Zhao's petition asking that her brother Ban Chao be relieved of his distant service is an important possible source. Preserved in the Book of the Later Han, it describes a man approaching seventy after decades abroad: his health has declined, and his physical strength may no longer follow his intentions if a crisis arises.

Her wording is 超之氣力，不能從心, rather than the exact four-character form. The same history also records 力不從心 in imperial correspondence about Western Regions states lacking the power to act as they wish. The idiom therefore expresses a mismatch between willingness and capacity, whether the limit is physical strength, resources, or practical ability.