The Prophet ﷺ said, "The first matter to be judged between people on the Day of Judgment will concern bloodshed."
قال النبي ﷺ: أول ما يقضى بين الناس بالدماء.
Bukhari narrated it in the Book of Softening of Hearts (6533), and Muslim in the Book of Qasama (1678), both (6533) from the hadith of Amash, who said, Shaqiq told me, he said, I heard Abdullah, and he related it.