Sayyiduna Sa'd bin Ubadah (may Allah be pleased with him) said to the Prophet (peace and blessings be upon him) that his mother had passed away while he was away from her; would it benefit her if he gave charity on her behalf? He (peace and blessings be upon him) said: "Yes." He said: Then I call you to witness that the two gardens of al-Mikhraf are charity on her behalf.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5351