The Messenger of Allah ﷺ would say in his bowing, "Glory be to my Lord, the Most Great," three times, and in his prostration, "Glory be to my Lord, the Most High."
أن رسول الله ﷺ كان يسبح في ركوعه سبحان ربي العظيم ثلاثا، وفي سجوده سبحان ربي الأعلى.
Bazzar reported it in Kashf Astar (538) from Muhammad bin Salih bin Awwam, from Abdul-Rahman bin Bakkar bin Abdul-Aziz bin Abu Bakra, from his father, from his grandfather, from Abu Bakra, and he mentioned it.Its chain is hasan because of Bakkar bin Abdul-Aziz bin Abu Bakra, for his hadith is hasan when it has a basis and he does not err in it. This is why Ibn Adi said, "I hope there is no harm in him."