The Messenger of Allah ﷺ said, "Before the Hour there will come days in which knowledge will be taken away, ignorance will descend, and harj will increase." He explained, "Harj means killing."
حدثنا أبو النضر حدثنا الأشجعي عن سفيان عن الأعمش عن أبي وائل
قال رسول الله ﷺ إن بين يدي الساعة أياما يرفع فيهن العلم وينزل فيهن الجهل ويكثر فيهن الهرج قال والهرج القتل
Its isnad is sahih. Ashjai is Ubaydullah bin Abdul-Rahman, in the diminutive form for both names, whose reliability was established earlier at 487, and he is one of Ahmad's teachers. Ahmad sometimes narrates from him through his son Abu Ubayda Ashjai, as in 487 and 2805, and sometimes through someone else, as here. Sufyan is Thawri. The hadith is a repetition of 3695.