Sahih al-Bukhari 1388
صحيح البخاري#1388SahihNarrated Aisha:A man said to the Prophet (ﷺ), "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 (ﷺ) replied in the affirmative
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 23:140