Abu Hurairah reported,

We were present with the Messenger of Allah ﷺ at Khaybar. He said about a man who claimed to be a Muslim, "This one is among the people of the Fire."When the battle began, the man fought fiercely and was wounded. Someone said, "Messenger of Allah, the man you said was among the people of the Fire fought fiercely today and has died."The Prophet ﷺ said, "He goes to the Fire."Some people were on the verge of doubting, when suddenly it was said that he had not died but was severely wounded. During the night, unable to bear his wounds, he killed himself. The Prophet ﷺ was informed of this and said, "Allah is the greatest. I bear witness that I am the slave of Allah and His Messenger."Then he ordered Bilal to announce to the people, "None shall enter Paradise except a Muslim soul, and indeed Allah supports this religion even through a wicked man."In another narration, We were present with the Messenger of Allah ﷺ at Khaybar. The Messenger of Allah ﷺ said about a man among those with him who claimed to be a Muslim, "This one is among the people of the Fire."When the battle began, the man fought with the fiercest fighting and sustained many wounds, which incapacitated him. A man from among the companions of the Prophet ﷺ came and said, "Messenger of Allah, do you realize that the one you said was among the people of the Fire has fought in the path of Allah with the fiercest fighting and has been covered in wounds?"The Prophet ﷺ said, "He is indeed among the people of the Fire."Some of the Muslims were on the verge of doubting, when, while in that state, the man felt the pain of his wounds, reached his hand to his quiver, drew out an arrow, and killed himself with it. Some men of the Muslims hurried to the Messenger of Allah ﷺ and said, "Messenger of Allah, Allah has confirmed your statement. So-and-so has stabbed himself and taken his own life."The Messenger of Allah ﷺ said, "Bilal, stand up and announce, 'None shall enter Paradise except a believer, and indeed Allah supports this religion even through a wicked man.'"

عن أبي هريرة، قال

شهدنا مع رسول الله ﷺ خيبر فقال لرجل ممن يدعي الإسلام: هذا من أهل النار. فلما حضر القتال قاتل الرجل قتالا شديدا، فأصابته. جراحة. فقيل: يا رسول الله الذي قلت إنه من أهل النار فإنه قد قاتل اليوم قتالا شديدا، وقد مات! فقال النبي ﷺ: إلى النار. قال: فكاد بعض الناس أن يرتاب فبينما هم على ذلك، إذ قيل: إنه لم يمت، ولكن به جراحا شديدا. فلما كان من الليل لم يصبر على الجراح فقتل نفسه، فأخبر النبي ﷺ بذلك فقال: الله أكبر! أشهد أني عبد الله ورسوله. ثم أمر بلالا فنادى بالناس: إنه لا يدخل الجنة إلا نفس مسلمة، وإن الله ليؤيد هذا الدين بالرجل الفاجر. وفي رواية: شهدنا مع رسول الله ﷺ خيبر فقال رسول الله ﷺ الرجل ممن معه يدعي الإسلام: هذا من أهل النار. فلما حضر القتال قاتل الرجل من أشد القتال، وكثرت به الجراح فأثبتته فجاء رجل من أصحاب النبي ﷺ فقال: يا رسول الله أرأيت الذي تحدثت أنه من أهل النار قد قاتل في سبيل الله من أشد القتال، فكثرت به الجراح، فقال النبي ﷺ: أما إنه من أهل النار. فكاد بعض المسلمين يرتاب فبينما هو على ذلك إذ وجد الرجل ألم الجراح فأهوى بيده إلى كنانته فانتزع منها سهما فانتحر بها فاشتد رجال من المسلمين إلى رسول الله ﷺ فقالوا: يا رسول الله، صدق الله حديثك قد انتحر فلان، فقتل نفسه فقال رسول الله ﷺ: يا بلال قم فأذن: لا يدخل الجنة إلا مؤمن، وإن الله ليؤيد هذا الدين بالرجل الفاجر.