Sahih Bukhari
Funerals (Al-Janaaiz)
Volume: 002 / Book Number: 023 / Hadith Number: 470
Narrated Aisha:
A man said to the Prophet (p.b.u.h), "My mother died suddenly and I thought that if she had lived she would have given alms. So, if I give alms now on her behalf, will she get the reward?" The Prophet replied in the affirmative.