´Ikrimah narrated from Ibn Abbas that :` a man said: "O Messenger of Allah! My mother died, will it benefit her if I give charity on her behalf?" He said: 'Yes.' He said: 'I have a Makhraf, so bear witness that I have given it in charity on her behalf.'"
Hadith Referenceسنن ترمذي / كتاب الزكاة عن رسول الله صلى الله عليه وسلم / 669