From Sahih Bukhari (Hadith 794):
Narrated `Aisha:The Prophet (ﷺ) used to say in his bowing and prostrations, "Subhanaka l-lahumma Rabbana wa bihamdika; Allahumma ghfir li.' (Exalted [from unbecoming attributes] Are you O Allah our Lord, and by Your praise [do I exalt You]. O Allah! Forgive me
Reference: Bukhari 794