On the day of Khaybar, a group of the Prophet's ﷺ companions came forward and began saying, "So-and-so is a martyr, so-and-so is a martyr," until they passed by a certain man and said, "So-and-so is a martyr."The Messenger of Allah ﷺ said, "Not at all. I have seen him in the Fire because of a cloak he stole," or "an outer garment."Then the Messenger of Allah ﷺ said, "Ibn al-Khattab, go and announce to the people that none shall enter Paradise except the believers."He said, "So I went out and called, 'None shall enter Paradise except the believers.'"
لما كان يوم خيبر أقبل نفر من صحابة النبي ﷺ فقالوا: فلان شهيد، فلان شهيد حتى مروا على رجل فقالوا فلان شهيد فقال رسول الله ﷺ: كلا إني رأيته في النار في بردة غلها أو عباءة ثم قال رسول الله ﷺ: يا ابن الخطاب اذهب فناد في الناس أنه لا يدخل الجنة إلا المؤمنون قال: فخرجت فناديت: ألا إنه لا يدخل الجنة إلا المؤمنون.
Muslim narrated it in the Book of Faith (114), from Zuhayr bin Harb, who said, "Hashim bin Qasim narrated to us, Ikrima bin Ammar narrated to us, Simak Hanafi Abu Zumayl narrated to me, Abdullah bin Abbas narrated to me, Umar bin Khattab narrated to me," and he related it.