Musnad Abu Ya'la al-Mawsili 252:40

Abu Bakr ibn Abi Shaybah narrated to us, Khalid ibn Makhlad narrated to us, from Muhammad ibn Ja'far ibn Abi Kathir, he said: Abu Hazim narrated to me, from Sahl ibn Sa'd, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The people will be gathered on the Day of Resurrection upon a white, reddish earth, like a pure loaf of bread, in which there is no landmark for anyone."