Hadith: Among the portents of the Hour is that knowledge will be taken away

عَنْ أَنَسٍ رَضِيَ اللَّهُ عَنْهُ، قَالَ: لَأُحَدِّثَنَّكُمْ حَدِيثًا سَمِعْتُهُ مِنْ رَسُولِ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ لاَ يُحَدِّثُكُمْ بِهِ أَحَدٌ غَيْرِي: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «إِنَّ مِنْ أَشْرَاطِ السَّاعَةِ أَنْ يُرْفَعَ العِلْمُ، وَيَكْثُرَ الجَهْلُ، وَيَكْثُرَ الزِّنَا، وَيَكْثُرَ شُرْبُ الخَمْرِ، وَيَقِلَّ الرِّجَالُ، وَيَكْثُرَ النِّسَاءُ حَتَّى يَكُونَ لِخَمْسِينَ امْرَأَةً القَيِّمُ الوَاحِدُ».
[صحيح] - [متفق عليه]

Anas (may Allah be pleased with him) said: I will narrate to you a Hadīth I heard from the Prophet (may Allah’s peace and blessings be upon him) and none will narrate it to you after me. I heard the Prophet (may Allah’s peace and blessings be upon him) say: "Among the portents of the Hour is that knowledge will be taken away, ignorance will prevail, adultery will spread, drinking alcohol will be common, and men will decrease in number while women will increase so much that for fifty women there will only be one man to look after them."
Sahih/Authentic. - [Al-Bukhari and Muslim]

Explanation

Anas (may Allah be pleased with him) said: I will relate to you a Hadīth I heard from the Prophet (may Allah’s peace and blessings be upon him) that none will relate to you but me. This is because he was one of the last surviving Companions. Or he probably meant that he alone was with the Prophet (may Allah’s peace and blessings be upon him) when he said this Hadīth, and he thought it was highly likely that the Prophet (may Allah’s peace and blessings be upon him) did not make the same statement again. I heard the Prophet (may Allah’s peace and blessings be upon him) say: Among the portents of the Hour is that knowledge will be taken away, which will happen by the death of scholars, as indicated by another Hadīth that reads: "Verily, Allah does not take away knowledge by snatching it from the people but He takes away knowledge by taking away the scholars." Other portents include the prevalence of ignorance, adultery, and alcoholic drinking, and that men will decrease in number and women increase so much that there will be for every fifty women only one man to take care of them and their interests. The intended meaning may be that women will be so large in number, not the exact number mentioned in the Hadīth. Mention of the increase in women's numbers is consistent with the mention of taking knowledge away and the prevalence of ignorance, for most scholars are men.