ʻUmar ibn Al-Khattaab, may Allaah be pleased with him, said, "By Allaah, no diyyah (blood money) is due to him (this man) from her." If the woman was killed while trying to prevent someone from violating her, she is a martyr. The Prophet said, "Whoever is killed while defending his honor is a martyr." [At-Tirmithi: good] I want to know whether this hadith is authentic or weak. Please explain it more so that I clearly understand what killing while defending one's honour means.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.

We did not find a hadeeth with this wording in the hadeeth books available to us. A similar hadeeth was reported by At-Tirmithi with the words "his family" not "his honor", and they are close in meaning. Saʻeed ibn Zayd reported that he heard the Prophet say, "Whoever is killed while defending his wealth is a martyr. Whoever is killed while defending his religion is a martyr. Whoever is killed while defending his blood (his life) is a martyr. Whoever is killed while defending his family is a martyr." [At-Tirmithi graded it hasan saheeh (sound or good) and Al-Albaani graded it saheeh (sound)]

As for the manner of warding off the attacker, the Muslim, male or female, is allowed to fight off the person who attacks his or her honor by the least defensive action that repels the attack. It is impermissible to kill the attacker if it is possible to stop him with a less drastic measure. If he cannot ward off the attacker except by killing him, then he may do that, and there is no sin or blood money upon the killer because he killed him to ward off his evil.

Ibn Qudaamah wrote:

"When a person attacks someone to seize his money or his life, then the ruling applied to an intruder entering his house (to rob or harm him) applies to this case; the attacked person is entitled to ward off the attacker with the least means to repel the assault. If there is a wide river or a ditch or a fortress between them that the attacker cannot cross, then the attacked person is not entitled to shoot the attacker. If he cannot ward off the attacker except by fighting him off and killing him, then he may do that. (Imaam) Ahmad advised that when a Muslim is attacked by thieves trying to rob him from his money or kill him, he is allowed to fight them off and defend himself and his wealth ... Ahmad said about a woman attacked by a man attempting to violate her honor and who killed him in self-defense, 'If she knew that he only attacked her to violate her honor and she killed him in the process of defending herself, then she bears no sin for that and is not liable for anything.' He mentioned the hadeeth that Az-Zuhri reported from Al-Qaasim ibn Muhammad on the authority of ʻUbayd ibn ʻUmayr in which he said that a man hosted guests from (the tribe of) Huthayl and pursued a woman and wanted (to rape) her; so she threw a rock at him and killed him. ʻUmar (ibn Al-Khattaab) said, 'By Allaah, there is no diyah (blood money) for him ever,' i.e., she did not have to pay the 'blood money' for him. If it is permissible to defend one's money, which one can give away, then a woman defending and protecting herself and her honor, which cannot be given away, is clearly more permissible than a man defending his money. If this is clear, then she is allowed to defend herself if she can for a greater reason because engaging in adultery (by not defending herself) is prohibited..." [Al-Mughni]

Al-Baghawi wrote:

"If a man attempts to rape a woman and she killed him to protect herself, she is not at fault. It has been reported to ʻUmar that a man pursued a slave girl as she was gathering wood and attempted to rape her. She threw a rock at him and killed him. Thereupon, ʻUmar said, 'He is killed by the right of Allaah. By Allaah, there is no diyah for him ever.' Ibn Al-Mulaqqin declared this report's chain of narration hasan (good) in his book Al-Badr Al-Muneer. Shuʻayb Al-Arnaa’oot declared it hasan in his revision of Saheeh Ibn Hibbaan; he wrote, 'This report was cited by ʻAbd Ar-Razzaaq in his Musannaf no. 17919, and by Al-Bayhaqi (8/337) with a chain of narration of trustworthy narrators..." [Sharh As-Sunnah]

Allaah knows best.