keep your powder dry
保留力量或資源，以備不時之需
口語·勸人保持準備
英文釋義
to be prepared and ready for a future opportunity or event; to exercise caution and restraint in order to protect oneself
例句
We don't know when the job market will improve, so keep your powder dry and save your money.
典故來源
源自17世紀的火藥時代，士兵需保持火藥干燥以確保槍支可用，引申為隨時做好準備。