Sunan an-Nasai Book 11, Hadith 968

أَخْبَرَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، عَنْ سُلَيْمٍ، - وَهُوَ ابْنُ أَخْضَرَ - عَنِ التَّيْمِيِّ، قَالَ حَدَّثَنِي بَكْرُ بْنُ عَبْدِ اللَّهِ الْمُزَنِيُّ، عَنْ أَبِي رَافِعٍ، قَالَ صَلَّيْتُ خَلْفَ أَبِي هُرَيْرَةَ صَلاَةَ الْعِشَاءِ - يَعْنِي الْعَتَمَةَ - فَقَرَأَ سُورَةَ ‏{‏ إِذَا السَّمَاءُ انْشَقَّتْ ‏}‏ فَسَجَدَ فِيهَا فَلَمَّا فَرَغَ قُلْتُ يَا أَبَا هُرَيْرَةَ هَذِهِ - يَعْنِي سَجْدَةً - مَا كُنَّا نَسْجُدُهَا ‏.‏ قَالَ سَجَدَ بِهَا أَبُو الْقَاسِمِ صلى الله عليه وسلم وَأَنَا خَلْفَهُ فَلاَ أَزَالُ أَسْجُدُ بِهَا حَتَّى أَلْقَى أَبَا الْقَاسِمِ صلى الله عليه وسلم ‏.‏

It was narrated that Abu Rafi' said:"I prayed Isha' prayer- meaning Al-'Atamah behind Abu Hurairah and he recited: 'When the heaven is split asunder' and prostrated during it. When he had finished praying, I said: 'O Abu Hurairah, (this is) a prostration that we are not used to.' He said: 'Abu Al-Qasim (ﷺ) did this prostration and I was (praying) behind him, and I will continue to do this prostration until I meet Abu Al-Qasim