(1) باب قَوْلِ اللَّهِ تَعَالَى {وَمَنْ يَقْتُلْ مُؤْمِنًا مُتَعَمِّدًا جَزَاؤُهُ فَجَهَنَّمُ}
Narrated `Abdullah:
The Prophet (ﷺ) said, "The first cases to be decided among the people (on the Day of Resurrection) will be those of blood-shed."
Reference: Sahih al-Bukhari 6864
In-book reference: Book 87, Hadith 4
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 83, Hadith 4