Rebel suggested Daffodils. I like it. I use it. You may also.
It means whatever you do to someone else, they have the right to do it to you and they should and will do it to you. It falls just short of "must do it to you." The right to pursue action remains a choice.
It is a conscious decision by others to apply what you mean for them onto you.
It means when this is done to you, you may not complain. You may not seek recourse. The only thing you can do is accept what happens.
It's more than justice. More than the Old Testament law "an eye for an eye."
It's more than The Golden Rule.
It's more than just desserts.
It means the person making the first move doesn't think it through. The first person suffers from cognitive dissonance, disconnection from reality.
It's making you shut up and live with the consequences of your actions.
What's good for the goose is good for the gander comes about a close as anything in English to explaining this. Yet, this too falls short.
If grok is the face of a coin, then daffodils may be considered the other side.