ENOfficial
Sahl b. Sa'd reported God's messenger as saying, "On the day of resurrection mankind will be assembled on a white plain with a reddish tinge like a loaf of white bread with no mark set up for anyone.'' (Bukhari and Muslim.)
Source: sunnah.com
Other translations
Arabic
عَنْ سَهْلِ بْنِ سَعْدٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «يُحْشَرُ النَّاسُ يَوْمَ الْقِيَامَةِ عَلَى أَرْضٍ بَيْضَاءَ عَفْرَاءَ كَقُرْصَةِ النَّقِيِّ لَيْسَ فِيهَا عَلَمٌ لأحدٍ» . مُتَّفق عَلَيْهِ
sunnah.com