Musnad Ahmad 25:1649

Rawh narrated to us, Ibn Jurayj narrated to us, he said: Ya'la informed me that he heard 'Ikrimah, the freed slave of Ibn 'Abbas, saying: Ibn 'Abbas informed us: That the mother of Sa'd ibn 'Ubadah died while he was absent from her. He came to the Messenger of Allah (peace be upon him) and said: "O Messenger of Allah, my mother has died while I was absent from her. Will it benefit her if I give charity on her behalf?" He said: "Yes." He said: "Then I call you to witness that my garden, the *Mukhraf* (fruit-bearing garden), is charity on her behalf."