Silsilat al-Ahadith al-Sahihah

Khalid bin Dehqan says: We were at the place of Dhalqiyah during the battle of Constantinople, when a man from among the most noble and honorable people of Palestine came to us. His name was Hani bin Kulthum bin Sharik Kanani. He greeted Abdullah bin Abu Zakariya, and he recognized his right. Khalid told us: Abdullah bin Zakariya narrated to us, he says that I heard Sayyidah Umm Darda (may Allah be pleased with her) say: I heard Sayyiduna Abu Darda (may Allah be pleased with him) say: I heard the Messenger of Allah (peace and blessings be upon him) say: "It is possible that Allah will forgive every sinner, except the one who dies in a state of shirk or a believer who intentionally kills another believer."