the Prophet said: "When one of you bows then says while he is bowing: (Subhana Rabbiyal Azim) 'Glorious is my Lord the Magnificent' three times, then he has completed his bowing. And that is the least of it. And when he prostrates and says while prostrating: (Subhana Rabbiyal A'la) 'Glorious is my Lord the Most High' three times, then he has completed his prostrations, and that is the least of it.'"  

أَنَّ النَّبِيَّ ﷺ قَالَ إِذَا رَكَعَ أَحَدُكُمْ فَقَالَ فِي رُكُوعِهِ سُبْحَانَ رَبِّيَ الْعَظِيمِ ثَلاَثَ مَرَّاتٍ فَقَدْ تَمَّ رُكُوعُهُ وَذَلِكَ أَدْنَاهُ وَإِذَا سَجَدَ فَقَالَ فِي سُجُودِهِ سُبْحَانَ رَبِّيَ الأَعْلَى ثَلاَثَ مَرَّاتٍ فَقَدْ تَمَّ سُجُودُهُ وَذَلِكَ أَدْنَاهُ قَالَ وَفِي الْبَابِ عَنْ حُذَيْفَةَ وَعُقْبَةَ بْنِ عَامِرٍ  

he performed Salat with the Prophet, and that while he was bowing he would say: (Subhana Rabbiyal Azim); "Glorious is my Lord the Magnificent" and while prostrating: (Subhana Rabbiyal A'la) 'Glorious is my Lord the Most High.' And he would not recite an Ayah mentioning mercy, except that he would stop and ask (for mercy), and he would not recite an Ayah mentioning punishment, except that he would stop and seek refuge (with Allah from it).  

أَنَّهُ صَلَّى مَعَ النَّبِيِّ ﷺ فَكَانَ يَقُولُ فِي رُكُوعِهِ سُبْحَانَ رَبِّيَ الْعَظِيمِ وَفِي سُجُودِهِ سُبْحَانَ رَبِّيَ الأَعْلَى وَمَا أَتَى عَلَى آيَةِ رَحْمَةٍ إِلاَّ وَقَفَ وَسَأَلَ وَمَا أَتَى عَلَى آيَةِ عَذَابٍ إِلاَّ وَقَفَ وَتَعَوَّذَ  

from another route: "That he performed Salat during the night with the Prophet" and he mentioned the Hadith.  

عَنْ حُذَيْفَةَ هَذَا الْحَدِيثُ مِنْ غَيْرِ هَذَا الْوَجْهِ أَنَّهُ صَلَّى بِاللَّيْلِ مَعَ النَّبِيِّ ﷺ فَذَكَرَ الْحَدِيثَ