Sahih Muslim 875
صحيح مسلم#875SahihUbada b. as-Samit reported:The Messenger of Allah (ﷺ) said: He who does not recite Umm al-Qur'an is not credited with having observed the prayer
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.
In-book reference: 4:38