What is the origin of the idiom "slap on the wrist" and when to use it?

The idiom "slap on the wrist" originated from the idea of giving someone a light physical punishment by lightly hitting their wrist. It is used to describe a mild or lenient form of reprimand or penalty for someone's wrongdoing. The phrase suggests that the punishment is not severe and does not effectively discourage or correct the behavior. It has been in use for a long time and is commonly used to express disapproval when a punishment is seen as too lenient or ineffective.