Narrated Ibn ‘Abbas:
The mother of Sad bin ‘Ubada died in his absence. He said, “O Allah’s Apostle! My mother died in my absence; will it be of any benefit for her if I give Sadaqa on her behalf?” The Prophet said, “Yes,” Sad said, “I make you a witness that I gave my garden called Al Makhraf in charity on her behalf.”
Sahih Bukhari, Volume 4, Book51, Number 19