أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ الزُّهْرِيُّ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ أَيُّوبَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ صَلَّيْتُ مَعَ النَّبِيِّ صلى الله عليه وسلم وَمَعَ أَبِي بَكْرٍ وَعُمَرَ - رضى الله عنهما - فَافْتَتَحُوا بِـ { الْحَمْدُ لِلَّهِ رَبِّ الْعَالَمِينَ }
It was narrated from Anas: "I prayed with the Prophet (PBUH) and with Abu Bakr and Umar, may Allah be pleased with them both, and they started with "All the praise and thanks be to Allah, the Lord of all that exists." Translation Not Available
Book Ref: Sunan An Nisai Book 11 Hadith 903
Web Ref: Sunan An Nisai Vol 2 Book 11 Hadith 904