Sunan an Nasai
The Book of the Commencement of the Prayer
Hadith #91
11.91
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا الْمُعْتَمِرُ، عَنْ قُرَّةَ، عَنِ ابْنِ سِيرِينَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ سَجَدَ أَبُو بَكْرٍ وَعُمَرُ - رضى الله عنهما - وَمَنْ هُوَ خَيْرٌ مِنْهُمَا صلى الله عليه وسلم فِي { إِذَا السَّمَاءُ انْشَقَّتْ } وَ { اقْرَأْ بِاسْمِ رَبِّكَ } .
It was narrated that Abu Hurairah said:"Abu Bakr and Umar, may Allah be pleased with them both, and the one who was better than them prostrated during 'When the heaven is split asunder' and 'Read! In the name of your Lord