It is narrated from Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) that one day the Messenger of Allah (peace and blessings be upon him) said to his Companions: "What do you say about a man who is killed in the path of Allah?" The Companions said: Paradise (he will go to). the Messenger of Allah (peace and blessings be upon him) said: "Paradise, if Allah wills." He (peace and blessings be upon him) said: "What do you say about a man who dies in the path of Allah?" The Companions said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "Paradise, if Allah wills." He (peace and blessings be upon him) said: "What do you say about a man who dies, and two upright men stand and say: We know nothing of him but good?" The Companions said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "Paradise, if Allah wills." He (peace and blessings be upon him) said: "What do you say about a man who dies, and two upright men stand and say: We know no good of him?" The Companions said: The Fire (he will go to). the Messenger of Allah (peace and blessings be upon him) said: "He is a sinner, and Allah is Most Forgiving, Most Merciful."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16373