Sahih Bukhari Volume 3, Book 29, Hadith 1879

حَدَّثَنَا عَلِيٌّ، حَدَّثَنَا سُفْيَانُ، حَدَّثَنَا ابْنُ شِهَابٍ، قَالَ أَخْبَرَنِي عُرْوَةُ، سَمِعْتُ أُسَامَةَ ـ رضى الله عنه ـ قَالَ أَشْرَفَ النَّبِيُّ صلى الله عليه وسلم عَلَى أُطُمٍ مِنْ آطَامِ الْمَدِينَةِ فَقَالَ ‏"‏ هَلْ تَرَوْنَ مَا أَرَى إِنِّي لأَرَى مَوَاقِعَ الْفِتَنِ خِلاَلَ بُيُوتِكُمْ كَمَوَاقِعِ الْقَطْرِ ‏"‏‏.‏ تَابَعَهُ مَعْمَرٌ وَسُلَيْمَانُ بْنُ كَثِيرٍ عَنِ الزُّهْرِيِّ‏.

Narrated By Usama : Once the Prophet stood at the top of a (looked out from upon one) castle amongst the castles (or the high buildings) of Medina and said, "Do you see what I see? (No doubt) I see the spots where afflictions will take place among your houses (and these afflictions will be) as numerous as the spots where rain-drops fall."