I was sitting with 'Abdullah and Abu Musa that they reported Messenger of Allah ﷺ having said: Prior to the Last Hour, there would be a time when knowledge would be taken away, and ignorance would take its place and there would be bloodshed on a large scale. (Using translation from Muslim 2672a)
كُنْتُ جَالِسًا مَعَ عَبْدِ اللهِ وَأَبِي مُوسَى وَهُمَا يَتَحَدَّثَانِ فَقَالَا قَالَ رَسُولُ اللهِ ﷺ بَيْنَ يَدَيِ السَّاعَةِ أَيَّامٌ يُرْفَعُ فِيهَا الْعِلْمُ وَيَنْزِلُ فِيهِنَّ الْجَهْلُ وَيَظْهَرُ فِيهِنَّ الْهَرْجُ وَالْهَرْجُ الْقَتْلُ