With this evidence that the statement of the Noble Prophet صلی اللہ علیہ وسلم : "When the Imam says 'Sami' Allahu liman hamidah', you should say 'Rabbana lakal hamd'"—by this, the Prophet صلی اللہ علیہ وسلم did not mean that after the Imam raises his head from bowing, he cannot recite anything more than 'Rabbana lakal hamd'.

It is narrated from Sayyiduna Rifa’ah bin Rafi’ (may Allah be pleased with him) that he said: One day we were praying behind the Messenger of Allah (peace and blessings of Allah be upon him). Then when he raised his head from bowing (ruku’), he said: «‏‏‏‏سَمِعَ اللهُ لِمَنْ حَمِدَهُ» ‏‏‏‏, so a man standing behind the Messenger of Allah (peace and blessings of Allah be upon him) recited this supplication: «‏‏‏‏رَبَّنَا وَلَكَ الحَمْدُ حَمْدًا كَثِيرًا طَيِّبًا مُبَارَكًا فِيهِ» ‏‏‏‏“O our Lord, to You belongs all praise, abundant, pure, and blessed praise (is for You).”Then when the Messenger of Allah (peace and blessings of Allah be upon him) finished the prayer with salam, he asked:“Who just spoke?”That person replied:“I did.”So the Messenger of Allah (peace and blessings of Allah be upon him) said:“Indeed, I saw more than thirty angels rushing to see who would write down these words first.”