Sunan Ibn Majah, Hadith 2615 ⓘ
It was narrated from Abdullah that the Messenger of Allah said: “The first matter concerning which judgment will be passed among the people on the Day of Resurrection will be bloodshed.”
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، وَعَلِيُّ بْنُ مُحَمَّدٍ، وَمُحَمَّدُ بْنُ بَشَّارٍ، قَالُوا حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا الأَعْمَشُ، عَنْ شَقِيقٍ، عَنْ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَوَّلُ مَا يُقْضَى بَيْنَ النَّاسِ يَوْمَ الْقِيَامَةِ فِي الدِّمَاءِ " .
also referenced under: Book 21, Hadith 2713 (In-Book) & Volume 3, Book 21, Hadith 2615 (DarusSalam)