Is it permissible to kill the father who asked his wife to engage in an illicit relationship with his friend, or to kill the friend who engaged in this relationship with her?

The father's request for the mother to commit a heinous act does not permit the son to kill him, for Allah Almighty says: "And whoever kills a believer intentionally, his recompense is Hell to abide therein, and Allah has become angry with him and has cursed him and has prepared for him a great torment." The son must advise the father, and if he cannot, then he must prevent the act from happening. The mother must gently strive to prevent herself from repeating that act. The mother's continued stay with the husband in this manner corrupts her religion and morals, and she should seek a divorce or khul'. The son should assist her in this.