Sunan an-Nasa'i 965
It was narrated that Abu Hurairah said:
"Abu Bakr and Umar prostrated during: 'When the heaven is split asunder,' as did the one who was better than them (the Prophet (ﷺ)). "
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا قُرَّةُ بْنُ خَالِدٍ، عَنْ مُحَمَّدِ بْنِ سِيرِينَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ سَجَدَ أَبُو بَكْرٍ وَعُمَرُ - رضى الله عنهما - فِي ‏{‏ إِذَا السَّمَاءُ انْشَقَّتْ ‏}‏ وَمَنْ هُوَ خَيْرٌ مِنْهُمَا ‏.‏