preach to the choir
对已经同意的人进行说教
口语·表示说服对象已同意
英文释义
to try to persuade or convince someone who already agrees with you or supports your cause
例句
You're telling us to recycle, but we already do—you're preaching to the choir.
典故来源
源自教堂布道，牧师对已经信教的唱诗班说教，比喻对已同意者多费口舌。