Sahih Bukhari
Wills and Testaments (Wasaayaa)
Volume: 004 / Book Number: 051 / Hadith Number: 31
Narrated Ibn Abbas:
A man said to Allah's Apostle , "My mother died, will it benefit her if I give in charity on her behalf?" The Prophet replied in the affirmative. The man said, "I have a garden and I make you a witness that I give it in charity on her behalf."