Sahih Muslim Book 39, Hadith Number 6708.
Chapter : Pertaining to re-birth. assembling and characteristics of the earth on the day of Resurrection.
Sahl b. Sa’d reported that Allah’s Messenger (may peace be upon him) said: The people will be assembled on tee Day of Resurrection on a white plain with a reddish tinge like the loaf of white bread with no marks set up for anyone.