Sahih al-Bukhari 2748
صحيح البخاري#2748SahihNarrated Abu Huraira:A man asked the Prophet, "O Allah's Messenger (ﷺ)! What kind of charity is the best?" He replied. "To give in charity when you are healthy and greedy hoping to be wealthy and afraid of becoming poor. Don't delay giving in charity till the time when you are on the death bed when you say, 'Give so much to so-and-so and so much to so-and-so,' and at that time the property is not yours but it belongs to so-and-so (i.e. your inheritors)
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: 55:11