Sahih Muslim
The Book of Bequests (Kitab Al-Wasiyya)
Book Number: 013 / Hadith Number: 4001
Abu Huraira (Allah be pleased with him) reported that a person said to Allah's Apostle (may peace be upon him): My father died and left behind property without making any will regarding it. Would he be relieved of the burden of his sing if I give sadaqa on his behalf? He (the Holy Prophet) said: Yea.