Sahih Muslim Book 5, Hadith Number 2196.

‘Aisha said that a person came to the Apostle of Allah (may peace be upon him) and said: My mother died suddenly without having made any will. I think she would have definitely given Sadaqa if she had been able to speak. Would she have a reward if I gave Sadaqa on her behalf? He (the Holy Prophet) said: Yes. This Hadith has been narrated on the authority of Hisham with the same chain of transmitters. And in the Hadith transmitted by Abu Usama the words are: “She did not make any will,” as it has been reported by Ibn Bishr, but it was not reported by the rest of the narrators.