Sahih Muslim 1992
صحيح مسلم#1992SahihIyas b. Salama b. al-Akwa' reported on the authority of his father:We used to observe the Friday prayer with the Messenger of Allah (ﷺ) when the sun passed the meridian. and we then returned and tried to find out afternoon shadow (of the walls for protecting themselves from the heat of the sun)
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: 7:42