My father died and left behind property without making any will regarding it. Would he be relieved of the burden of his sins if I give sadaqa on his behalf? He (the Holy Prophet) said: Yes.
Sahih Muslim Book 25, Hadith 16
← Previous Hadith (I wish) if people would reduce from third to fourth (part for making a will of their property), for Allah's Messenger (ﷺ) said: So far as the third (part) is concerned it is quite substantial. In the hadith transmitted on the authority of Waki (the words are)" large" or" much".

Sahih Muslim Book 25, Hadith 15 Next Hadith → My mother died all of a sudden, and I think if she (could have the opportunity) to speak she would have (made a will) regarding Sadaqa'. Will I be entitled to reward if I give charity on her behalf? He (the Holy Prophet) said: Yes.

Sahih Muslim Book 25, Hadith 17