حَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا عَفَّانُ، حَدَّثَنَا حَمَّادٌ، أَخْبَرَنَا ثَابِتٌ، عَنْ أَنَسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لاَ تَقُومُ السَّاعَةُ حَتَّى لاَ يُقَالَ فِي الأَرْضِ اللَّهُ اللَّهُ " .
It is narrated on the authority of Anas that verily the Messenger of Allah (PBUH) said: "The Hour (Resurrection) will not occur until 'Allah, Allah' is not said on earth." Translation Not Available
Book Ref: Sahih Muslim Book 1 Hadith 273
Web Ref: Sahih Muslim Book 1 Hadith 148 a