Sahih Bukhari
Virtues and Merits of the Prophet (pbuh) and his Companions
Volume: 004 / Book Number: 056 / Hadith Number: 841
Narrated Abu Huraira:
I said, "O Allah's Apostle! I hear many narrations from you but I forget them." He said, "Spread your covering sheet." I spread my sheet and he moved both his hands as if scooping something and emptied them in the sheet and said, "Wrap it." I wrapped it round my body, and since then I have never forgotten a single Hadith.