Maliks Muwatta Book 36, Hadith Number 54.
Section : Sadaqa of the Living for the Dead.
Malik related to me that he heard that a man of the Ansar from the tribe of Banu al-Harith ibn al-Khazraj, gave sadaqa to his parents and then they died. Their son inherited the property he had given them and it was palm-trees. He asked the Messenger of Allah, may Allah bless him and grant him peace, about it and he said, “You are rewarded for your sadaqa, and take it as your inheritance.”