صحيح البخاري

Narrated Ibn `Abbas:

That the mother of Sa`d bin Ubada the brother of Bani Saida died in Sa`d's absence, so he came to the Prophet saying, "O Allah's Messenger! My mother died in my absence, will it benefit her if I give in charity on her behalf?" The Prophet (ﷺ) said, "Yes." Sa`d said, "I take you as my witness that I give my garden Al-Makhraf in charity on her behalf."