Sahih Bukhari
Virtues and Merits of the Prophet (pbuh) and his Companions
Volume: 004 / Book Number: 056 / Hadith Number: 754
Narrated Ibn Abbas:
The Prophet was the most generous of all the people, and he used to become more generous in Ramadan when Gabriel met him. Gabriel used to meet him every night during Ramadan to revise the Qur'an with him. Allah's Apostle then used to be more generous than the fast wind.