(1) باب قَوْلِ اللَّهِ تَعَالَى {وَمَنْ يَقْتُلْ مُؤْمِنًا مُتَعَمِّدًا جَزَاؤُهُ فَجَهَنَّمُ}
Narrated `Abdullah bin `Umar:
One of the evil deeds with bad consequence from which there is no escape for the one who is involved in it is to kill someone unlawfully.
Reference: Sahih al-Bukhari 6863
In-book reference: Book 87, Hadith 3
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 83, Hadith 3