حَدَّثَنَا حَفْصُ بْنُ عُمَرَ قَالَ حَدَّثَنَا شُعْبَةُ عَنْ قَتَادَةَ عَنْ أَنَسِ بْنِ مَالِکٍ أَنَّ النَّبِيَّ صَلَّی اللَّهُ عَلَيْهِ وَسَلَّمَ وَأَبَا بَکْرٍ وَعُمَرَ رَضِيَ اللَّهُ عَنْهُمَا کَانُوا يَفْتَتِحُونَ الصَّلَاةَ بِ الْحَمْدُ لِلَّهِ رَبِّ الْعَالَمِينَ
صحیح بخاری · Hadith 743
Narrated Anas bin Malik: The Prophet, Abu Bakr and `Umar used to start the prayer with "Al hamdu li l-lahi Rabbi l-`alamin (All praise is but to Allah, Lord of the Worlds).
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020