كتاب تحريم الدم
Read the English translation first, with the original Arabic directly underneath.
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 [ﷺ]." He said: "I heard him delivering a Khutbah and he said: 'I heard the Messenger of Allah [ﷺ] say: Every sin may be forgiven by Allah except a man who kills a believer deliberately, or a man who dies as a disbeliever.'"
كُلُّ ذَنْبٍ عَسَى اللَّهُ أَنْ يَغْفِرَهُ إِلاَّ الرَّجُلُ يَقْتُلُ الْمُؤْمِنَ مُتَعَمِّدًا أَوِ الرَّجُلُ يَمُوتُ كَافِرًا