saving for a rainy day
未雨绸缪；存钱以备不时之需
口语·未雨绸缪
英文释义
setting aside money or resources for future needs or emergencies
例句
She's been saving for a rainy day since she got her first job.
典故来源
与save money for a rainy day同源，16世纪谚语，强调预防性储蓄。