It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) would say in his bowing: 'Subhana rabbiyal-'azim' (Glory be to my Lord, the Most Great), repeating this glorification again and again. Then, when he raised his head from bowing, he would say: 'Sami'Allahu liman hamidah, rabbana wa lakal-hamd' (Allah has heard the one who praised Him. O our Lord, to You alone belongs all praise). When he prostrated, he would say: 'Subhana rabbiyal-a'la' (Glory be to my Lord, the Most High), repeating this phrase again and again as well, and on raising his head from prostration he would recite this supplication: 'Rabbighfir li' (O Allah, forgive me).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2681