Sahih al-Bukhari 6864
Sahih al-Bukhari · Book 87: Blood Money (Ad-Diyat) · “… And whoever kills a believer intentionally, his recompense is Hell …”
Narrated `Abdullah:
حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُوسَى ، عَنِ الأَعْمَشِ ، عَنْ أَبِي وَائِلٍ ، عَنْ عَبْدِ اللَّهِ ، قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم " أَوَّلُ مَا يُقْضَى بَيْنَ النَّاسِ فِي الدِّمَاءِ " .
The Prophet (ﷺ) said, "The first cases to be decided among the people (on the Day of Resurrection) will be those of blood-shed."