Sunan an-Nasa'i 961
It 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.
أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ يَزِيدَ، عَنْ أَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ، أَنَّ أَبَا هُرَيْرَةَ، قَرَأَ بِهِمْ ‏{‏ إِذَا السَّمَاءُ انْشَقَّتْ ‏}‏ فَسَجَدَ فِيهَا فَلَمَّا انْصَرَفَ أَخْبَرَهُمْ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم سَجَدَ فِيهَا ‏.‏