Musnad Ahmad 25:1221

'Abd al-Razzaq and Ibn Bakr narrated to us, they said: Ibn Jurayj informed us, he said: Ya'la informed me that he heard 'Ikrimah, the freed slave of Ibn 'Abbas, saying: Ibn 'Abbas informed us: That Sa'd ibn 'Ubadah—Ibn Bakr said: the brother of Banu Sa'idah—his mother died while he was absent from her. He said: "O Messenger of Allah, my mother 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, al-Mikhraf, is charity on her behalf." And Ibn Bakr said: "al-Mikhraf."