Sahih Muslim 1382
صحيح مسلم#1382SahihA'isha reported:The Apostle of Allah (ﷺ) said the afternoon" prayer as the sun shone in my apartment, and the afternoon shadow did not extend further. Abu Bakr said: The afternoon shadow did not appear to extend further
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: 5:216