The Book of Faith
1/66. Chapter:
The Disappearance of Faith at the End of Time
Sahih Muslim
حَدَّثَنَا عَبْدُ بْنُ حُمَيْدٍ، أَخْبَرَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا مَعْمَرٌ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لاَ تَقُومُ السَّاعَةُ عَلَى أَحَدٍ يَقُولُ اللَّهُ اللَّهُ " .
It is narrated on the authority of Anas that the Messenger of Allah (ﷺ) said: "The Hour (Resurrection) will not occur as long as anyone says: 'Allah, Allah.'"
Reference : Sahih Muslim 148bIn-book reference : Book 1, Hadith 283USC-MSA web (English) reference : Book 1, Hadith 274