Sahih al-Bukhari 6521

Sa'id ibn Abi Maryam narrated to us; Muhammad ibn Ja'far informed us; Abu Hazim narrated to me, who said: I heard Sahl ibn Sa'd say: I heard the Prophet, peace and blessings be upon him, say: ‘On the Day of Resurrection, people will be gathered on a white, reddish-tinged earth, like a loaf made of pure flour.’ Sahl or someone else said: It will have no landmarks for anyone.