The Messenger of Allah ﷺ would often say in his bowing and prostration, "Glory be to You, our Lord, and praise be to You. O Allah, forgive me."
أخبرنا إسمعيل بن مسعود قال حدثنا خالد ويزيد قالا حدثنا شعبة عن منصور عن أبي الضحى عن مسروق
كان رسول الله ﷺ يكثر أن يقول في ركوعه وسجوده سبحانك ربنا وبحمدك اللهم اغفر لي
Bukhari transmitted it in the Book of Adhan, chapter on supplication during ruku, hadith no. 794, through the narration of Shubah. Muslim transmitted it in the Book of Prayer, chapter on what is said during ruku and sujud, hadith no. 484, through the narration of Mansur, with the same wording. It is also found in Al-Kubra, hadith no. 635.