临渴掘井

Origin and story

The Suwen's Siqi tiaoshen dalun chapter argues that action should precede a crisis. Waiting until illness or disorder has taken hold is compared to digging a well only after becoming thirsty, or making weapons once fighting has begun. Its wording is 渴而穿井, a direct predecessor of the familiar image.

The Yanzi chunqiu uses a related comparison about hurried well-digging after choking, showing a wider tradition of criticizing belated preparation. The later idiom makes thirst the immediate problem and digging the time-consuming response. In everyday use, it warns that a resource needed urgently cannot always be created at the moment it is needed.