to be not for somebody to say
01
to believe that it is not someone's place to make a decision or judgment on a particular matter and that it should be left to others who are more qualified or have more authority to do so
例子
It is not for him to say whether we should go or stay.
Look, I agree with you, she should be punished for what happened. But she's not our daughter, so it's not for us to say!
