Narrated Abu Huraira:
We were in the company of Allah's Apostle in a Ghazwa, and he remarked about a man who claimed to be a Muslim, saying, "This (man) is from the people of the (Hell) Fire." When the battle started, the man fought violently till he got wounded. Somebody said, "O Allah's Apostle! The man whom you described as being from the people of the (Hell) Fire fought violently today and died." The Prophet ﷺ said, "He will go to the (Hell) Fire." Some people were on the point of doubting (the truth of what the Prophet had said) while they were in this state, suddenly someone said that he was still alive but severely wounded. When night fell, he lost patience and committed suicide. The Prophet was informed of that, and he said, "Allah is Greater! I testify that I am Allah's Slave and His Apostle." Then he ordered Bilal to announce amongst the people: 'None will enter Paradise but a Muslim, and Allah may support this religion (i.e. Islam) even with a disobedient man.'
Sahih al-Bukhari, Vol. 4, Book of Jihaad, Hadith 297
Sahih al-Bukhari, Book of Jihaad, Hadith 297