Sunan an-Nasa'i 1116
سنن النسائي#1116SahihIt was narrated that Anas said:"When he prayed Zuhr behind the Messenger of Allah (ﷺ) we would prostrate on our garments because of the heat
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 12:88