Sunan an-Nasa'i 961
سنن النسائي#961SahihIt was narrated from Abu Salamah bin Abdur- Rahman that:Abu Hurairah (led them in prayer and) recited: "When the heaven is split asunder." and prostrated during it. When he had finished praying, he told them that the Messenger of Allah (ﷺ) had prostrated during it
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 Muslim
In-book reference: 11:86