Is a triple divorce and a pronouncement of Ẓihār valid if uttered during menstruation, by saying, "You are divorced by three and you are to me as the back of my mother," and what are the resulting rulings, such as the requirement of a new contract for reconciliation and the necessity of expiation for Ẓihār?

Most scholars are of the opinion that the divorce of a menstruating woman is effective, and that uttering the word "three" for divorce counts as three divorces. This is the fatwa.

Based on this, the wife has become irrevocably divorced from her husband with a major divorce (baynunah kubra). He cannot take her back unless she marries another man willingly, and then he divorces her or dies, and her waiting period (iddah) expires.

As for the ẓihār (a pre-Islamic form of divorce by likening one's wife to one's mother) uttered by the husband after the triple divorce, it does not take effect because it occurred after the finality of the divorce and therefore did not apply to a wife still under his marital bond.