كتاب الفتن وأشراط الساعة
54
The Book of Tribulations and Portents of the Last Hour
(18)
Chapter: The Hour Will Not Begin Until A Man Passes By Another Man's Grave And Wishes That He Was In The Place Of The Deceased, Because Of Calamity
(18)
بَاب لَا تَقُومُ السَّاعَةُ حَتَّى يَمُرَّ الرَّجُلُ بِقَبْرِ الرَّجُلِ فَيَتَمَنَّى أَنْ يَكُونَ مَكَانَ الْمَيِّتِ مِنْ الْبَلَاءِ

Abu Huraira reported Allah's Messenger (ﷺ) as saying:

The Last Hour would not come until the Muslims fight with the Turks-a people whose faces would be like hammered shields wearing clothes of hair and walking (with shoes) of hair.
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا يَعْقُوبُ، - يَعْنِي ابْنَ عَبْدِ الرَّحْمَنِ - عَنْ سُهَيْلٍ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ لاَ تَقُومُ السَّاعَةُ حَتَّى يُقَاتِلَ الْمُسْلِمُونَ التُّرْكَ قَوْمًا وُجُوهُهُمْ كَالْمَجَانِّ الْمُطْرَقَةِ يَلْبَسُونَ الشَّعَرَ وَيَمْشُونَ فِي الشَّعَرِ ‏"‏ ‏.‏
Reference : Sahih Muslim 2912 d
In-book reference : Book 54, Hadith 79
USC-MSA web (English) reference : Book 41, Hadith 6959
  (deprecated numbering scheme)