Sahih Muslim 1350
صحيح مسلم#1350SahihKa'b b. 'Ujra reported Allah's Messenger (ﷺ) as saying:There are certain ejaculations, the repeaters of which or the performers of which at the end of every prayer will never be caused disappointment:" Glory be to Allah" thirty-three times," Praise be to Allah" thirty-three times, and" Allah is most Great" thirty-four times
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.