Sahih Bukhari
Beginning of Creation
Volume: 004 / Book Number: 054 / Hadith Number: 443
Narrated Ibn 'Abbas:
Allah's Apostle was the most generous of all the people, and he used to be more generous in the month of Ramadan when Gabriel used to meet him. Gabriel used to meet him every night in Ramadan to study the Holy Quran carefully together. Allah's Apostle used to become more generous than the fast wind when he met Gabriel