It is narrated from Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) that there was a man who was among the most useful of the Muslims to the Muslims in a battle he fought alongside the Messenger of Allah (peace and blessings be upon him). The Messenger of Allah (peace and blessings be upon him) looked at him and said: "Whoever wishes to see one of the people of Hell, let him look at this man." So a man from among the people followed him, while he was in that state, fighting most fiercely against the polytheists, until he was wounded. Hastening his death, he took the point of his sword and placed it between his breasts, until it came out from between his shoulders. Then that man came hurrying to the Messenger of Allah (peace and blessings be upon him) and said: I bear witness that you are the Messenger of Allah. The Messenger of Allah (peace and blessings be upon him) said: "How so?" He said: You said: "Whoever wishes to see one of the people of Hell, let him look at this man," while he was the most useful of us, so I was certain he would not die in that state. When he was wounded, he hastened his death and killed himself. At that the Messenger of Allah (peace and blessings be upon him) said: "A servant does the deeds of the people of Paradise while he is of the people of Hell, and does the deeds of the people of Hell while he is of the people of Paradise. Deeds are judged only by their endings."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5763