(1) باب
It was narrated that Abu Idris said:
"I heard Mu'awiyah delivering the Khutbah, and he narrated a few Hadiths from the Messenger of Allah [SAW]." He said: "I heard him delivering a Khutbah and he said: 'I heard the Messenger of Allah [SAW] say: Every sin may be forgiven by Allah except a man who kills a believer deliberately, or a man who dies as a disbeliever.'"
Reference: Sunan an-Nasa'i 3984
In-book reference: Book 37, Hadith 19
English translation: Vol. 5, Book 37, Hadith 3989