Can a wife be sexually intimate with her husband after he has said, "You are unlawful to me as a brother is unlawful to his sister," and the wife has paid the expiation, or must the husband pay it?

A man's statement to his wife: "You are as forbidden to me as a brother is forbidden to his sister" is a kinayah (allusive remark) that requires intention. If he intended zihar (a pre-Islamic Arabian custom of divorce where a husband would declare his wife to be like his mother or sister, making her unlawful to him), then he must offer the kaffarat az-zihar (expiation for zihar): freeing a slave, or fasting for two consecutive months, or feeding sixty needy people, in that specific order, all before resuming conjugal relations. If he intended divorce, then it is a divorce. If he intended an oath (yamin), then he must offer the kaffarat al-yamin (expiation for breaking an oath). It is permissible for the wife to pay the kaffarat al-yamin with her husband's permission, as it is a financial act of worship. However, in the case of zihar, the wife's payment of the expiation is not sufficient unless the husband is unable to free a slave or fast, and then he gives her permission to feed the needy.