Sahih Muslim
The Book Pertaining to the Turmoil and Portents of the Last Hour (Kitab Al-Fitan wa Ashrat As-Saah)
Book Number: 041 / Hadith Number: 6998
Abu Sa'id reported that Ibn Sayyad asked Allah's Messenger (may peace be upon him) about the earth of Paradise. Whereupon he said: It is like white shining pure musk.