Sahih al-Bukhari 5362
صحيح البخاري#5362SahihNarrated `Ali bin Abi Talib:Fatima came to the Prophet (ﷺ) asking for a servant. He said, "May I inform you of something better than that? When you go to bed, recite "Subhan Allah' thirty three times, 'Al hamduli l-lah' thirty three times, and 'Allahu Akbar' thirty four times. `Ali added, 'I have never failed to recite it ever since." Somebody asked, "Even on the night of the battle of Siffin?" He said, "Even on the night of the battle of Siffin
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: 69:12