Who is authorized to determine the mahr (dower) for grooms, what is its amount, and is the marriage contract valid without it?

The determination of the dowry (sadaq) is left to the woman and her guardian. If they differ, the reference point is the dowry of her peers (mahr al-mithl). There is no specific limit for the dowry; rather, it is what the two parties agree upon, but it is recommended to lighten and facilitate it. The dowry is obligatory in marriage, and after agreement, it becomes an exclusive right of the woman. It is not permissible for the guardian to take anything from it except with her consent. The woman may waive all or part of the dowry to her husband after the contract if she is of sound judgment. If the marriage takes place without a dowry, it is valid, and the woman is entitled to the dowry of her peers.