Jami` at-Tirmidhi, Volume 3, Book 14, Hadith 1397 (DarusSalam) ⓘ
'Abdullah narrated that the Messenger of Allah said: "Indeed the first cases to be judged between the worshippers are those of bloodshed."
حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا وَكِيعٌ، عَنِ الأَعْمَشِ، عَنْ أَبِي وَائِلٍ، عَنْ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ أَوَّلَ مَا يُقْضَى بَيْنَ الْعِبَادِ فِي الدِّمَاءِ " .
also referenced under: Hadith 1397 (Reference) & Book 16, Hadith 13 (In-Book)