Sahih Muslim Book - 4, Hadith - 1085

حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ وَإِسْحَاقُ بْنُ إِبْرَاهِيمَ قَالَ زُهَيْرٌ حَدَّثَنَا جَرِيرٌ عَنْ مَنْصُورٍ عَنْ أَبِى الضُّحَى عَنْ مَسْرُوقٍ عَنْ عَائِشَةَ قَالَتْ كَانَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- يُكْثِرُ أَنْ يَقُولَ فِى رُكُوعِهِ وَسُجُودِهِ « سُبْحَانَكَ اللَّهُمَّ رَبَّنَا وَبِحَمْدِكَ اللَّهُمَّ اغْفِرْ لِى ». يَتَأَوَّلُ الْقُرْآنَ.

It was narrated that 'Aishah said: "The Messenger of Allah (s.a.w) often used to say when he was bowing and prostrating: 'Subhanak Allahumma! Wa bihamdika, Allahummaghfirli (Glory and praise be to You, O Allah our Lord. O Allah, forgive me,)' acting in accordance with the (command of) the Qur'an.