The Book Pertaining to the Turmoil and Portents of the Last Hour (Kitab Al-Fitan wa Ashrat As-Sa`ah)
Muslim :: Book 41 : Hadith 6997
This hadith has transmitted on the authority of Abu Sa'id that Allah's Messenger (may peace be upon him) asked Ibn Sa'id about the earth of Paradise. Thereupon he said: Abu'l-Qasim, It is like a fine white musk, whereupon he (the Holy Prophet) said: 'You have told the the truth.