“The Messenger of Allah ﷺ said: ‘When anyone of you bows, let him say in his bowing: “Subhana Rabbiyal-‘Azim (Glory is to my Lord, the Most Great)” three times; if he does that his bowing will be complete. And when anyone of you prostrates, let him say in his prostration, ‘Subhana Rabbiyal-A’la (Glory if to my Lord, the Most High)” three times; if he does that, his prostration will be complete, and that is the minimum.’” (Using translation from Ibn Mājah 890)
"إِذَا ركع أحدُكُمْ فليُقلْ في رُكوعُه: سبحانَ ربِّى الْعَظيم، ثلاثًا،
فإِذا فعلَ ذلكَ فقد تمَّ (ركوعُه، وذلك أدناه، وإِذا سَجَدَ فليقلْ في سجوده: سبحانَ ربى الأعلى، ثلاثًا، فإِذا فعل ذلك فقد تمَّ) سجودُه، وذلك أدناه.