Sahih Muslim 1012
صحيح مسلم#1012SahihAbu Qatada reported:The Messenger of Allah (ﷺ) led us in prayer and recited in the first two rak'ahs of the noon and afternoon prayers Surat al-Fitiha and two (other) surahs. And he would sometimes recite loud enough for us the verses. He would prolong the first rak'ah more than the second. And he acted similarly in the morning 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: 4:174