Abdur Rahman bin 'Amr al-Awza'i عبد الرحمن بن عمرو أبو عمرو الأوزاعي · The Book of Wills

"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.

"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?'…

"When a man dies all his good deeds come to an end except three: Ongoing charity (Sadaqah Jariyah), beneficial knowledge and a righteous son who prays for him."

"O Messenger of Allah, my mother has died; can I give charity on her behalf?" He said: "Yes." He said: "What kind of charity is best?" He said: "Providing drinking water." And that is the drinking-fountain of Sa'd in Al-Madinah.

"The Messenger of Allah said to me: 'O Abu Dharr, I think that you are weak, and I like for you what I like for myself. Do not accept a position of Amir over two people, and do not agree to be the guardian of an orphan's property.'"