"My mother died unexpectedly; if she had been able to speak she would have given charity. Should I give charity on her behalf?" The Messenger of Allah said: "Yes." So he gave charity on her behalf.
Sunan an-Nasa'i Book 30, Hadith 39
← Previous Hadith "When this verse- 'And warn your tribe (O Muhammad) of near kindred'- was revealed, the Messenger of Allah said: 'O Fatimah, daughter of Muhammad! O Safiyyah bint 'Abdul-Muttalib! O Banu 'Abdul-Muttalib! I cannot avail you anything before Allah; ask me for whatever you want of my wealth.'"

Sunan an-Nasa'i Book 30, Hadith 38 Next Hadith → "Sa'd bin 'Ubadah went out with the Prophet on one of his campaigns, and death came to his mother in Al-Madinah. It was said to her (as she was dying): 'Make a will.' She said: 'To whom shall I make a will? The wealth belongs to Sa'd.' Then she died before Sa'd came. When Sa'd came, he was told about that and he said: 'O Messenger of Allah, will it benefit her if I give in charity on her behalf?' The Prophet said: 'Yes.' Sa'd said: 'Such and such a garden is given in charity on her behalf' -regarding a garden that he named."

Sunan an-Nasa'i Book 30, Hadith 40