Sahih Muslim 1684
صحيح مسلم#1684SahihA'isha reported that the Messenger of Allah (ﷺ) observed two rak'ahs of the dawn prayer and he shortened them (to the extent) that I (out of surprise) said:Did he recite in them Surah Fatiha (only)?
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: 6:114