Sahih al-bukhari:119 Chapter: The superiority of knowledge Book 3, Hadith 61

Narrated Abu Huraira: I said to Allah’s Messenger (ﷺ) “I hear many narrations (Hadiths) from you but I forget them.” Allah’s
Apostle said, “Spread your Rida’ (garment).” I did accordingly and then he moved his hands as if
filling them with something (and emptied them in my Rida’) and then said, “Take and wrap this sheet
over your body.” I did it and after that I never forgot any thing. Narrated Ibrahim bin Al-Mundhir: Ibn Abi Fudaik narrated the same as above (Hadith…119) but added that the Prophet (ﷺ) had moved his
hands as if filling them with something and then he emptied them in the Rida’ of Abu Huraira.