From Sahih Muslim (Hadith 7351):
This hadith has transmitted on the authority of Abu Sa'id that Allah's Messenger (ﷺ) 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
Reference: Muslim 7351