Sahih al-Bukhari 795
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · What the Imam and the followers say on raising their heads from bowing.
Narrated Abu Huraira:
حَدَّثَنَا آدَمُ ، قَالَ حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ ، عَنْ سَعِيدٍ الْمَقْبُرِيِّ ، عَنْ أَبِي هُرَيْرَةَ ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم إِذَا قَالَ " سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ ". قَالَ " اللَّهُمَّ رَبَّنَا وَلَكَ الْحَمْدُ ". وَكَانَ النَّبِيُّ صلى الله عليه وسلم إِذَا رَكَعَ وَإِذَا رَفَعَ رَأْسَهُ يُكَبِّرُ، وَإِذَا قَامَ مِنَ السَّجْدَتَيْنِ قَالَ " اللَّهُ أَكْبَرُ " .
When the Prophet (ﷺ) said, "Sami`a l-lahu liman hamidah," (Allah heard those who sent praises to Him), he would say, "Rabbana wa laka l-hamd." On bowing and raising his head from it the Prophet (ﷺ) used to say Takbir. He also used to say Takbir on rising after the two prostrations. (See Hadith No. 656).