What is the ruling regarding a wife's refusal to donate her kidney to her husband, who is suffering from kidney failure, given her father's prohibition of it, and the husband's threat of divorce if she does not donate? Is her refusal to donate considered a sin, or would donating against her father's command be considered an act of disobedience?

The original ruling permits donating organs whose removal does not harm the donor. If the parents forbid it, their obedience is obligatory, and the husband's obedience does not take precedence over theirs. The wife does not sin by refraining from donating a kidney, even if it leads to divorce, because the husband's obedience that takes precedence over parents applies to matters that are his right, such as conjugal relations, not to what the wife owns in terms of money or organs. The questioner is advised to ask Allah for guidance towards rectitude, and he may seek the intercession of someone who influences his parents to persuade them of the benefit, if he sees the husband's need and no harm from the operation.