What is the ruling on shunning a person in eating, greeting, and speaking, preventing him from the student support fund, and imposing a financial penalty on anyone who talks to him or greets him? And what are the limits and duration of shunning in Islam?

The basic rule is that it is forbidden to ostracize a Muslim for more than three nights, unless he is the aggressor in a dispute, in which case it is permissible to ostracize him so that he may be deterred from his disobedience. Nevertheless, it is advisable to admonish and remind him instead of ostracizing him, especially if the period of ostracism is prolonged, and to pardon and forgive. As for depriving the aggressor of privileges, it is permissible if these privileges are created by students and are not a right guaranteed by the state; otherwise, he may not be deprived of his rights under any circumstances. If he is not the oppressor, then ostracism is a sin, and one must repent from it and reconcile with him.