Narrated 'Abdullah:

The Prophet ﷺ said, "Near the establishment of the Hour, there will be the days of Al-Harj, and the religious knowledge will be taken away (vanish i.e. by the death of Religious scholars) and general ignorance will spread." Abu Musa said, "Al-Harj, in the Ethiopian language, means killing," Ibn Mas'ud added: I heard Allah's Apostle saying;
(It will be) from among the most wicked people who will be living at the time when the Hour will be established."

حَدَّثَنَا مُحَمَّدٌ، حَدَّثَنَا غُنْدَرٌ، حَدَّثَنَا شُعْبَةُ، عَنْ وَاصِلٍ، عَنْ أَبِي وَائِلٍ، عَنْ عَبْدِ اللَّهِ، وَأَحْسِبُهُ، رَفَعَهُ قَالَ " بَيْنَ يَدَىِ السَّاعَةِ أَيَّامُ الْهَرْجِ، يَزُولُ الْعِلْمُ، وَيَظْهَرُ فِيهَا الْجَهْلُ ". قَالَ أَبُو مُوسَى وَالْهَرْجُ الْقَتْلُ بِلِسَانِ الْحَبَشَةِ.