The Chinese idiom "隔靴搔痒" is formed by sequentially combining four characters: 隔, meaning "to separate" or "from outside", 靴, meaning "boot", 搔, meaning "to scratch", and 痒, meaning "itch". These characters literally depict the action of scratching an itch through a boot, which is inherently ineffective, thus constructing a metaphorical phrase that describes attempting to solve a problem without direct access to its source, leading to futile results.