It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that a man said: O Messenger of Allah! My mother has died and she made no bequest; will it benefit her if I give charity on her behalf? He (peace and blessings be upon him) said: "Yes."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11580