money for old rope
不勞而獲，容易得到的東西或金錢
口語·形容不勞而獲
英文釋義
Easy money, effortless profit, or a valuable return for minimal effort
例句
Selling these old books online is money for old rope—they were just gathering dust.
典故來源
源于19世紀英國，舊繩子本無價值，但回收后仍可賣錢，比喻不費力的收益。