Question 2: Our tribe agreed that Mahr (mandatory gift to a bride from her groom) is to be twenty five thousand riyals only. If the bride’s brother or father receives more than this, the tribe takes the extra amount of money and put sit in a tribe box which is allocated for helping the Miskeen (needy) people. Is it then permissible to take this extra sum as a sort of punishing whomever violates the convention set by the tribe?
Answer: If the concerned tribe agreed on a certain Mahr for the interest of the young boys and girls amongst them, no one is allowed to violate such an agreement. This is because such violation is to threaten the general interest of the people of the town or the tribe... read more here.