Sahih Muslim Book 40, Hadith Number 6805.
Chapter : The description of the tents for the inmates of Paradise.
Abu Bakr b. Abdullah b. Qais reported on the authority of his father that Allah’s Messenger (may peace be upon him) said that in Paradise there would be a tent made of a single hollowed pearl, the breadth of which would be sixty miles from all sides and there would live a family in each corner and the other would not be able to see the believer who goes around them.