The Book of the Commencement of the Prayer
11/52. Chapter:
Prostration during: "Read! In the Name of your Lord"
Sunan an-Nasai
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.'"
Reference : Sunan an-Nasa'i 966In-book reference : Book 11, Hadith 91English translation : Vol. 2, Book 11, Hadith 967