That is because they listen to falsehood and eat what is forbidden. Therefore, if they come to you with their cases, you may judge between them or refuse to do so. Even if you refuse, they will not be able to harm you the least, but if you do act as a judge, judge between them with fairness, for Allah loves those who judge with fairness.
Meaning:-
forbidden: refuse to allow (something), prohibit, not allowed, banned.