Sahih Muslim 883
صحيح مسلم#883SahihAta' narrated on the authority of Abu Huraira who said that one should recite (al-Fatiha) in every (rak'ah of) prayer. What we heard (i. e. recitation) from the Messenger of Allah (ﷺ), we made you listen to that. And that which he (recited) inwardly, we (recited) inwardly for you. A person said to him:If I add nothing to the (recitation) of the Umm al Qur'an (Surat al-Fatiha), would it make the prayer incomplete? He (AbuHuraira) said: If you add to that (if you recite some of verses of the Qur'an along with Surat at-Fatiha) that is better for you. But if you are contented with it (Surat al-Fatiha) only, it is sufficient for you
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: 4:45