Umar ibn al-Khattab reported: The Messenger of Allah, peace and blessings be upon him, said, “Verily, among what I fear most for my nation is every hypocrite with a knowledgeable tongue.”
Source: Musnad Aḥmad 140
Grade: Sahih (authentic) according to Ahmad Shakir
عَنْ عُمَرَ بْنِ الْخَطَّابِ أَنّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِنَّ أَخْوَفَ مَا أَخَافُ عَلَى أُمَّتِي كُلُّ مُنَافِقٍ عَلِيمِ اللِّسَانِ
140 مسند أحمد بن حنبل
1/86 المحدث أحمد شاكر خلاصة حكم المحدث إسناده صحيح في مسند أحمد
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Abu Dhar said, Rasool Allah (صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ) said: "There is something I fear for my Ummah more than the Dajjal." I became afraid & asked: "Oh Rasool Allah! Which thing is that?" He (صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ) said; "Misguided and astray scholars."
[Musnad Ahmad (5/145) No. 21334/21335]
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Fazlur Rehman (Deobandi Sufi) did khuruj against Islamic government with the slogans of High price inflation! When the government was removed and his Khariji party took over, price of the Hajj was increased double than one legislated in the Previous government!