Sunan an-Nasa'i, Book 11, Hadith 31 (In-Book) ⓘ

It was narrated that Anas bin Malik said: "The Messenger of Allah led us in prayer, and we did not hear him recite: In the Name of Allah, the Most Gracious, the Most Merciful. And Abu Bakr and Umar led us in prayer and we did not hear it from them either."

أَخْبَرَنَا مُحَمَّدُ بْنُ عَلِيِّ بْنِ الْحَسَنِ بْنِ شَقِيقٍ، قَالَ سَمِعْتُ أَبِي يَقُولُ، أَنْبَأَنَا أَبُو حَمْزَةَ، عَنْ مَنْصُورِ بْنِ زَاذَانَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ صَلَّى بِنَا رَسُولُ اللَّهِ صلى الله عليه وسلم فَلَمْ يُسْمِعْنَا قِرَاءَةَ ‏{‏ بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ ‏}‏ وَصَلَّى بِنَا أَبُو بَكْرٍ وَعُمَرُ فَلَمْ نَسْمَعْهَا مِنْهُمَا ‏.‏