Sahih Muslim 1281
صحيح مسلم#1281SahihAbdullah (b. Mas'ud) reported:The Apostle of Allah (ﷺ) said five rak'ahs of the noon prayer and when he completed the prayer, It was said to him: Has there been (commanded) an addition In prayer? He said: What is it? They said: You have said five rak'ahs, so he performed two prostrations
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: 5:119