Sunan an-Nasa'i 902
سنن النسائي#902Sahihأَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم وَأَبُو بَكْرٍ وَعُمَرُ - رضى الله عنهما - يَسْتَفْتِحُونَ الْقِرَاءَةَ بِـ { الْحَمْدُ لِلَّهِ رَبِّ الْعَالَمِينَ }
It was narrated from Anas that:The Prophet (ﷺ), Abu Bakr, and Umar, may Allah be pleased with them both, would start their recitation with: "All the praise and thanks be to Allah, the Lord of all that exists
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu Ghuddah-
Zubair Ali ZaiSahih
In-book reference: 11:27