3984
Sahih+2
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
SahihAbu Ghuddah
SahihAl-Albani